Doctors Vamsi Velcheti, Sandip Patel, and Michael Zervos discuss recent updates on the management of early-stage non-small cell lung cancer (NSCLC), including the optimization of neoadjuvant and adjuvant treatment options for patients and the role of surgery in the era of targeted therapy and immuno-oncology in lung cancer.

TRANSCRIPT

Dr. Vamsi Velcheti: Hello, I'm Dr. Vamsi Velcheti, your guest host for the ASCO Daily News Podcast today. I am a professor of medicine and director of thoracic medical oncology at the Perlmutter Cancer Center at NYU Langone Health. On today's episode, we'll be discussing recent updates on the management of early-stage non-small cell lung cancer (NSCLC), including the optimization of neoadjuvant and adjuvant treatment options for our patients, and the evolving role of surgery in the era of targeted therapy and immuno-oncology in lung cancer. 

Today, I am delighted to be joined by two renowned experts in this space, Dr. Sandip Patel and Dr. Michael Zervos. Dr. Patel is a professor of medicine and a medical oncologist specializing in lung cancer at UCSD. Dr. Mike Zervos is the clinical chief of the Division of Robotic Thoracic Surgery and Director of General Thoracic Surgery at NYU Langone.

Our full disclosures are available in the transcript of this episode, and disclosures relating to all episodes of the podcast are available at asco.org/DNpod.

Dr. Patel and Dr. Zervos, it's a great honor to have you on the podcast today. Welcome aboard.

Dr. Sandip Patel: Great to be joining you. 

Dr. Vamsi Velcheti:  Let's get started with Dr. Patel. As you know, over the last decade we've had dramatic advances in systemic therapy options for patients with metastatic non-small cell lung cancer, in both the realms of targeted therapy and immunotherapy. These have significantly improved outcomes for our patients with metastatic lung cancer. What's exciting is that more recently, we've seen the incorporation of these agents, both targeted therapies and immunotherapies, in early-stage non-small cell lung cancer. Dr. Patel, can you tell our listeners about these exciting recent advances and why do you think it's so important to incorporate these personalized systemic therapy options for our early-stage patients?

Dr. Sandip Patel: I think it's a great point and a great question. And so, I think one thing to understand is that non-small cell lung cancer is actually multiple diseases. We give it one name based on how it looks under the microscope, but the vast majority of our advances to improve outcomes for patients have come from our ability to understand specific subgroups. 

Many of our therapies have had activity in the advanced setting. We have our patients with metastatic or more widespread disease, which naturally led to the thought that could we utilize these therapies in earlier stage disease and potentially increase the rate of cure for many of our patients, lung cancer being the most common cancer killer worldwide. And so to your point, trying to understand how to best treat a patient really involves personalized medicine, typically driven by understanding the genomic profile of their tumor and two of the genes that have graduated from being tested for in the metastatic setting and now in the localized setting are EGFR and ALK. And these in particular are mutations that confer sensitivity to small molecule inhibitors, EGFR with osimertinib, ALK in the localized setting with alectinib based on the data that we've seen. 

And so, one of the areas that's been particularly exciting is our ability to maximize a patient's chance for durable remissions by integrating these therapies after surgery, after chemotherapy when appropriate, and continuing generally for a finite amount of time, two to three years depending on the agent in the study we're discussing for these patients. Additionally, immunotherapy, which has revolutionized our treatment of patients with metastatic disease, may be particularly well-suited for the localized setting of non-small cell lung cancer as well.

Dr. Vamsi Velcheti: Excellent points, Sandip. You're absolutely right, in the metastatic setting, we've all come to accept molecular testing, sequencing, and biomarker profiling as a standard, but unfortunately, that hasn't quite yet percolated into the early-stage setting. Can you talk about some of the challenges that we face as we have these therapeutic options available now for more early-stage patients?

Dr. Sandip Patel: So, I think there are 3 flavors of localized therapy in non-small cell lung cancer. One is the advanced, unresectable stage 3, for which the approach is often concurrent chemo-radiation followed by some form of consolidated therapy. We're about to hear the results of LAURA, which is the study looking at EGFR-mutated non-small cell lung cancer. 

For other patients, historically, the treatment has been durvalumab, an anti-PD-L1 directed immunotherapy. The other two are operative treatment of localized cancer: adjuvant treatment after surgery, or neoadjuvant or perioperative, in which chemoimmunotherapy begins before surgery. And testing depends on the settings. For the stage 3 patient who's likely getting concurrent chemo-radiation, they may have a very small amount of tissue, and so often these are done by pulmonary EBUS biopsies and that’s how we pathologically confirm that advanced stage 3B. There may not be a lot of tissue available for molecular testing. In fact, if you look at the PACIFIC analysis, just looking at PD-L1, which is just an IHC off a single slide, a third of patients weren't able to even get a PD-L1, let alone a genomic result. And so, I think that's one of the areas of LAURA that's going to be particularly interesting to see as we try to implement it into our practice after seeing the full data. 

I think in the adjuvant setting, we're lucky because our surgeons, Dr. Mike Zervos here, will get us a large amount of tissue in the surgical resection specimen, so we tend to get enough tissue to do genomics while they're under chemotherapy, there tends to be time to wait for their genomic result. Where this really gets complicated is in the neoadjuvant or perioperative setting, where time is everything. 

The most important thing we can do for a patient in the localized space is get them to the operating room, get them started on radiation, their curative local modality, and that’s where we have a time pressure but also a sample pressure because that is a diagnostic biopsy. It’s a very small piece of tissue. Initially, there are multiple stains that have to be done to identify this lung cancer as opposed to another tumor. And so that’s an area that I think we’re going to need additional approaches given that cell-free DNA tends to have lower yield in lower stage disease in giving us a result.

Dr. Vamsi Velcheti: Great points, Sandip. How do you deal with this issue in San Diego? The challenge is now we have a lot of trials, we’ll talk about those neoadjuvant immunotherapy trials, but we know that immunotherapy may not be as effective in all patients, especially those with EGFR or ALK or some of these non-smoker, oncogene-driven tumors. So, we don’t want to be giving patients treatments that may not necessarily be effective in the neoadjuvant space, especially when there is a time crunch, and we want to get them to surgery and all the complications that come with giving them targeted therapy post-IO with potential risk for adverse events.

Dr. Sandip Patel: Absolutely. It is a great point. And so, the multidisciplinary team approach is key, and having a close relationship with the interventional pulmonary oncs, interventional radiology surgery, and radiation oncology to ensure that we get the best treatment for our patients. With the molecularly guided therapies, they are currently more on the adjuvant setting in terms of actually treating. But as you mentioned, when we’re making a decision around neoadjuvant or perioperative chemo IO, it’s actually the absence of EGFR now that we’re looking for because our intervention at the current time is to give chemoimmunotherapy. Going back to the future, we used to use single gene EGFR within 24 hours, which was insufficient for a metastatic panel, but it often required five slides of tissue input. ALK can be done by IHC, and so some of these ‘oldie but goodie’ pathologic techniques, and that pathologists, if I haven’t emphasized, understanding what we’re trying to do at a different context is so key because they are the ones who really hold the result. In the neoadjuvant and perioperative setting, which many of us favor, especially for stage 3A and stage 2B disease, understanding how we can get that result so that we can get the patient to the operating room in an expeditious way is so important. There is a time pressure that we always had in the metastatic setting, but I think we feel much more acutely in the neoadjuvant and perioperative setting in my opinion.

Dr. Vamsi Velcheti: Fascinating insights, Dr. Patel. 

Turning to Dr. Zervos, from a surgical perspective, there has been an evolution in terms of minimally invasive techniques, robotic approaches, and enhanced recovery protocols, significantly improving outcomes in our patients post-surgery. How do you see the role of surgery evolving, especially with the increasing complexity and efficacy of these systemic therapies? How do you envision the role of surgery in managing these early-stage patients, and what are the key considerations for surgeons in this new era?

Dr. Michael Zervos: Thanks, Vamsi. Thanks, Sandip. Thank you for having me on the podcast. Obviously, it's an honor to be a part of such a high-level discussion. I have to say, from a surgeon's perspective, we often listen to you guys talk and realize that there’s been a lot of change in this landscape. And I think the thing that I've seen is that the paradigm here has also changed. If we were having this discussion 10 years ago, a lot of the patients that I am operating on now, I would not be operating on. It really has been amazing. And I think the thing that stands out to me the most is how all of this has changed with neoadjuvant chemotherapy checkpoint inhibition. I think, for us as surgeons, that's really been the key. Whether it's CheckMate 816 or whatever you're following, like PACIFIC, the data supports this. And I think what we're seeing is that we're able to do the surgery, we’re able to do it safely, and I think that the resectability rates are definitely high up there in the 90% range. And what we’re seeing is pretty significant pathologic responses, which I think is really amazing to me. 

We're also seeing that this has now shifted over to the oligometastatic realm, and a lot of those patients are also being treated similarly and then getting surgery, which is something that we would not have even thought of ever. When you look at the trials, I think a lot of the surgery, up to this point, has been done more traditionally. There's a specific reason why that happens, specifically, more through thoracotomy, less with VATS, and less with robotic. Sandip, I think you guys have a pretty robust robotic program at UCSD, so I'm sure you're pretty used to seeing that.  

As you guys have become so much more sophisticated with the treatments, we have also had to modify what we do operatively to be able to step up to the plate and accept that challenge. But what we are seeing is yes, these treatments work, but the surgeries are slightly more complicated. And when I say slightly, I’m minimizing that a little bit.  And what's complicated about it is that the treatment effect is that the chemo-immune check inhibition actually has a significant response to the tumor antigen, which is the tumor. So it's going to necrose it, it’s going to fibrose it, and wherever there is a tumor, that response on the surgical baseline level is going to be significant. In other words, there are going to be lymph nodes that are stuck to the pulmonary artery, lymph nodes that are stuck to the airway, and we've had to modify our approaches to be able to address that.  

Now, fortunately, we've been able to innovate and use the existing technology to our advantage. Personally, I think robotics is the way we have progressed with all this, and we are doing these surgeries robotically, mainly because I think it is allowing us, not only to visualize things better, but to have sort of a better understanding of what we're looking at. And for that matter, we are able to do a better lymph node dissection, which is usually the key with a lot of these more complicated surgeries, and then really venturing out into more complicated things, like controlling the pulmonary artery. How do we address all this without having significant complications or injuries during the surgery? Getting these patients through after they’ve successfully completed their neoadjuvant treatment, getting them to surgery, doing the surgery successfully, and hopefully, with minimal to no morbidity, because at the end, they may be going on to further adjuvant treatment. All of these things I think are super important. I think although it has changed the landscape of how we think of things, it has made it slightly more complicated, but we are up for the challenge. I am definitely excited about all of this.

Dr. Vamsi Velcheti: For some reason, like medical oncologists, we only get fixated on the drugs and how much better we're doing, but we don't really talk much about the advances in surgery and the advances in terms of outcomes, like post-op mortality has gone down significantly, especially in larger tertiary care centers. So, our way of thinking, traditionally, the whole intergroup trials, the whole paradigm of pneumonectomies being bad and bad outcomes overall, I think we can't judge and decide on current treatment standards based on surgical standards from decades ago. And I think that's really important to recognize. 

Dr. Michael Zervos: All of this stuff has really changed over the past 10 years, and I think technology has helped us evolve over time. And as the science has evolved for you with the clinical trials, the technology has evolved for us to be able to compensate for that and to be able to deal with that. The data is real for this. Personally, what I'm seeing is that the data is better for this than it was for the old intergroup trials. We're able to do the surgery in a better, more efficient, and safer way. The majority of these surgeries for this are not going to be pneumonectomies, they are going to be mostly lobectomies. I think that makes sense. I think for the surgeons who might be listening, it doesn't really matter how you’re actually doing these operations. I think if you don't have a very extensive minimally invasive or robotic experience, doing the surgery as open is fine, as long as you’re doing the surgery safely and doing it to the standard that you might expect with complete lymph node clearance, mediastinal lymph node clearance, and intrapulmonary lymph node clearance. Really, I think that’s where we have to sort of drive home the point, really less about the actual approach, even though our bias is to do it robotically because we feel it’s less morbidity for the patient. The patients will recover faster from the treatment and then be able to go on to the next phase treatments.

Dr. Vamsi Velcheti: In some of the pre-operative trials, the neoadjuvant trials, there have been some concerns raised about 20% of patients not being able to make it to surgery after induction chemo immunotherapy. Can you comment on that, and why do you think that is the case, Sandip? 

Dr. Sandip Patel: Well, I think there are multiple reasons. If you look, about half due to progression of disease, which they might not have been great operative candidates to begin with, because they would have early progression afterwards. And some small minority in a given study, maybe 1% to 2%, it's an immune-related adverse event that’s severe. So, it’s something that we definitely need to think about. The flip side of that coin, only about 2 in 3 patients get adjuvant therapy, whether it be chemotherapy, immunotherapy, or targeted therapy. And so, our goal is to deliver a full multimodal package, where, of course, the local therapy is hugely important, but also many of these other molecular or immunologically guided agents have a substantial impact. 

And I do think the point around neoadjuvant and perioperative is well taken. I think this is a discussion we have to have with our patients. I think, in particular, when you look at higher stage disease, like stage 3A, for example, the risk-benefit calculus of giving therapy upfront given the really phenomenal outcomes we have seen, really frankly starting with the NADIM study, CheckMate816, now moving on into studies like KEYNOTE-671, AEGEAN, it really opens your eyes in stage 3. Now, for someone who’s stage 1/1b, is this a patient who’s eager to get a tumor out? Is there as much of an impact when we give neoadjuvant therapy, especially if they’re not going to respond and may progress from stage 1 and beyond? I think that’s a reasonable concern. How to handle stage II is very heterogeneous. I think two points that kind of happen as you give neoadjuvant therapy, especially chemo-IO that I think is worth for folks to understand and this goes to Mike’s earlier point, that is this concept if they do get a scan during your neoadjuvant chemo immunotherapy, there is a chance of that nodal flare, where the lymph nodes actually look worse and look like their disease is progressing. Their primary tumor may be smaller or maybe the same. But when we actually go to the OR, those lymph nodes are chock-full of immune cells. There’s actually no cancer in those lymph nodes. And so that’s a bit of a red herring to watch out for.  

And so, I think as we’re learning together how to deliver these therapies, because the curative-intent modality is, in my opinion, a local modality. It’s what Mike does in the OR, my colleagues here do in the OR. My goal is to maximize the chance of that or really maximize the long-term cure rates. And we know, even as long as the surgery can go, if only 2 or 3 patients are going to get adjuvant therapy then 1 in 10, of which half of those or 1 in 20, are not getting the surgery and that’s, of course, a big problem. It’s a concern. I think better selecting towards those patients and thinking about how to make these choices is going to be hugely important as we go over. Because in a clinical trial, it’s a very selective population. A real-world use of these treatments is different. I think one cautionary tale is that we don’t have an approval for the use of neoadjuvant or perioperative therapy for conversion therapy, meaning, someone who’s “borderline resectable.” At the time at which you meet the patient, they will be resectable at that moment. That’s where our best evidence is, at the current time, for neoadjuvant or perioperative approaches. 

Dr. Vamsi Velcheti:   I think the other major issue is like the optimal sequencing of immune checkpoint here. Obviously, at this point, we have multiple different trial readouts, and there are some options that patients can have just neoadjuvant without any adjuvant. Still, we have to figure out how to de-escalate post-surgery immunotherapy interventions. And I think there’s a lot of work that needs to be done, and you’re certainly involved in some of those exciting clinical trials. What do you do right now in your current clinical practice when you have patients who have a complete pathologic response to neoadjuvant immunotherapy? What is the discussion you have with your patients at that point? Do they need more immunotherapy, or are you ready to de-escalate? 

Dr. Sandip Patel: I think MRD-based technologies, cell-free DNA technologies will hopefully help us guide this. Right now, we are flying blind along two axes. One is we don’t actually know the contribution of the post-operative component for patients who get preoperative chemo-IO. And so this is actually going to be an ongoing discussion. And for a patient with a pCR, we know the outcomes are really quite good based on CheckMate816, which is a pure neoadjuvant or front-end only approach. Where I actually struggle is where patients who maybe have 50% tumor killing. If a patient has only 10% tumor killing ... the analogy I think in clinic is a traffic light, so the green light if you got a pCR, a yellow light if you have that anywhere from 20%-70% residual viable tumor, and then anything greater than that, you didn’t get that much with chemo-IO and you’re wondering if getting more chemo-IO, what would that actually do? It’s a bit of a red light.

And I’m curious, we don’t have any data, but my guess would be the benefit of the post-op IO is because patients are in that kind of yellow light zone. So maybe a couple more cycles, we’ll get them an even more durable response. But I am curious if we’re going to start relying more on MRD-based technologies to define treatment duration. But I think it’s a very complicated problem. I think folks want to balance toxicity, both medical and financial, with delivering a curative-intent therapy. And I am curious if this maybe, as we’re looking at some of the data, some of the reasons around preferring a perioperative approach where you scale it back, as opposed to a neoadjuvant-only approach where there’s not a clean way to add on therapy, if you think that makes sense. But it’s probably the most complicated discussions we have in clinic and the discussion around a non-pCR. And frankly, even the tumor board discussions around localized non-small cell lung cancer have gone very complex, for the benefit of our patients, though we just don’t have clean data to say this is the right path.  

Dr. Vamsi Velcheti: I think that the need for a really true multidisciplinary approach and discussing these patients in the tumor board has never been more significant. Large academic centers, we have the luxury of having all the expertise on hand. How do we scale this approach to the broader community is a big challenge, I think, especially in early-stage patients. Of course, not everyone can travel to Dr. Zervos or you for care at a large tertiary cancer centers. So, I think there needs to be a lot of effort in terms of trying to educate community surgeons, community oncologists on managing these patients. I think it’s going to be a challenge.

Dr. Michael Zervos: If I could just add one thing here, and I completely agree with everything that has been said. I think the challenge is knowing beforehand. Could you predict which patients are going to have a complete response? And for that matter, say, “Okay. Well, this one has a complete response. Do we necessarily need to operate on this patient?” And that’s really the big question that I add. I personally have seen some complete response, but what I’m mostly seeing is major pathologic response, not necessarily CR, but we are seeing more and more CR, I do have to say. The question is how are you going to predict that? Is looking for minimal residual disease after treatment going to be the way to do that? If you guys could speak to that, I think that is just tremendously interesting. 

Dr. Vamsi Velcheti: I think as Sandip said, MRD is looking very promising, but I just want to caution that it’s not ready for primetime clinical decision making yet. I am really excited about the MRD approach of selecting patients for de-escalation or escalation and surgery or no surgery. I think this is probably not quite there yet in terms of surgery or no surgery decision. Especially for patients who have early-stage cancer, we talk about curative-intent treatment here and surgery is a curative treatment, and not going to surgery is going to be a heavy lift. And I don’t think we're anywhere close to that. Yet, I’m glad that we are having those discussions, but I think it may be too hard at this point based on the available technologies to kind of predict CR. We’re not there. 

Dr. Michael Zervos: Can I ask you guys what your thought process is for evaluating the patient? So, when you're actually thinking about, “Hey, this patient actually had a good response. I'm going to ask the surgeons to come and take a look at this.” What imaging studies are you actually using? Are you just using strictly CT or are you looking for the PET? Should we also be thinking about restaging a lot of these patients? Because obviously, one of the things that I hate as a surgeon is getting into the operating room only to find out that I have multiple nodal stations that are positive. Which really, in my opinion, that's sort of a red flag. And for me, if I have that, I'm thinking more along the lines of not completing that surgery because I'm concerned about not being able to provide an R0 resection or even having surgical staple lines within proximity of cancer, which is not going to be good. It's going to be fraught with complications. 

So, a lot of the things that we as surgeons struggle with have to do with this. Personally, I like to evaluate the patients with an IV intravenous CT scan to get a better idea of the nodal involvement, proximity to major blood vessels, and potentially even a PET scan. And though I think in this day and age, a lot of the patients will get the PET beforehand, not necessarily get it approved afterwards. So that's a challenge. And then the one thing I do have to say that I definitely have found helpful is, if there's any question, doing the restaging or the re-EBUS at that point to be particularly helpful. 

Dr. Sandip Patel: Yeah, I would concur that having that pathologic nodal assessment is probably one of the most important things we can do for our patients. For a patient with multinodal positive disease, the honest truth is that at our tumor board, that patient is probably going to get definitive chemoradiation followed by their immunotherapy, or potentially soon, if they have an EGFR mutation, osimertinib. For those patients who are clean in the mediastinum and then potentially have nodal flare, oftentimes what our surgeons will do as the first stage of the operation, they'll actually have the EBUS repeated during that same anesthesia session and then go straight into surgery. And so far the vast majority of those patients have proceeded to go to surgery because all we found are immune cells in those lymph nodes. 

So, I think it's a great point that it's really the pathologic staging that's driving this and having a close relationship with our pathologists is key. But I think one point that I think we all could agree on is the way that we're going to find more of these patients to help and cure with these therapies is through improved utilization of low-dose CT screening in the appropriate population in primary care. And so, getting buy-in from our primary care doctors so that they can do the appropriate low-dose CT screening along with smoking cessation, and find these patients so that we can offer them these therapies, I think is something that we really, as a community, need to advocate on. Because a lot of what we do with next-generation therapies, at least on the medical oncology side, is kind of preaching to the choir. But getting the buy-in so we can find more of these cases at stage 1, 2 or 3, as opposed to stage 4, I think, is one of the ways we can really make a positive impact for patients.

Dr. Vamsi Velcheti: I just want to go back to Mike's point about the nodal, especially for those with nodal multistation disease. In my opinion, those anatomic unresectability is a moving target, especially with evolving, improving systemic therapy options. The utilization for chemo radiation has actually gone down. I think that's a different clinical subgroup that we need to kind of think differently in terms of how we do the next iteration or generation of clinical trials, are they really benefiting from chemo-IO induction? And maybe we can get a subset of those patients in surgery. I personally think surgery is probably a more optimal, higher yield to potentially cure these patients versus chemo radiation. But I think how we identify those patients is a big challenge. And maybe we should do a sequential approach induction chemo-IO with the intent to kind of restage them for surgery. And if they don't, they go to chemo consolidation radiation, I guess. So, I think we need to rethink our approach to those anatomically unresectable stage 3s. But I think it's fascinating that we're having these discussions. You know, we’ve come to accept chemo radiation as a gold standard, but now we're kind of challenging those assumptions, and I think that means we're really doing well in terms of systemic therapy options for our patients to drive increased cures for these patients.

Dr. Michael Zervos: I think from my perspective as a surgeon, if I'm looking at a CT scan and trying to evaluate whether a patient is resectable or not, one of the things that I'm looking for is the extent of the tumor, proximity to mediastinal invasion, lymph nodes size. But if that particular patient is resectable upfront, then usually, that patient that receives induction chemo checkpoint inhibition is going to be resectable afterwards. The ones that are harder are the ones that are borderline resectable upfront or not resectable. And then you're trying to figure out on the back end whether you can actually do the surgery.  Fortunately, we're not really taking many patients to the operating room under those circumstances to find that they're not resectable. Having said that, I did have one of those cases recently where I got in there and there were multiple lymph node stations that were positive. And I have to say that the CT really underestimated the extent of disease that I saw in the operating room. So, there are some challenges surrounding all of these things.

Dr. Sandip Patel: Absolutely. And I think for those patients, if upfront identification by EBUS showed multi nodal involvement, we've had excellent outcomes by working with radiation oncologists using modern radiotherapy techniques, with concurrent chemo radiation, followed by their immunotherapy, more targeted therapy, at least it looks like soon. I think finding the right path for the patient is so key, and I think getting that mediastinal pathologic assessment, as opposed to just guessing based on what the PET CT looks like, is so important. If you look at some of the series, 8% to 10% of patients will get a false-positive PET on their mediastinal lymph nodes due to coccidioidomycosis or sarcoidosis or various other things. And the flip side is there's a false-negative rate as well. I think Mike summarized that as well, so I think imaging is helpful, but for me, imaging is really just pointing the target at where we need to get pathologic sampling, most commonly by EBUS. And getting our interventional pulmonary colleagues to help us do that, I think is so important because we have really nice therapeutic options, whether it's curative-intent surgery, curative-intent chemo radiation, where we as medical oncologists can really contribute to that curative-intent local therapy, in my opinion. 

Dr. Vamsi Velcheti: Thank you so much Sandip and Mike, it's been an amazing and insightful discussion, with a really dynamic interplay between systemic therapy and surgical innovations. These are really exciting times for our patients and for us. Thank you so much for sharing your expertise and insights with us today on the ASCO Daily News Podcast.  

I want to also thank our listeners today for your time. If you value the insights that you hear today, please take a moment to rate, review, and subscribe to the podcast wherever you get your podcasts. Thank you so much. [FH1]  

Dr. Sandip Patel: Thank you.

Dr. Michael Zervos: Thank you.

 

Disclaimer:

The purpose of this podcast is to educate and to inform. This is not a substitute for professional medical care and is not intended for use in the diagnosis or treatment of individual conditions.

Guests on this podcast express their own opinions, experience, and conclusions. Guest statements on the podcast do not express the opinions of ASCO. The mention of any product, service, organization, activity, or therapy should not be construed as an ASCO endorsement.

 

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Disclosures: 

Dr. Vamsidhar Velcheti:

Honoraria: ITeos Therapeutics

Consulting or Advisory Role: Bristol-Myers Squibb, Merck, Foundation Medicine, AstraZeneca/MedImmune, Novartis, Lilly, EMD Serono, GSK, Amgen, Elevation Oncology, Taiho Oncology, Merus

Research Funding (Inst.): Genentech, Trovagene, Eisai, OncoPlex Diagnostics, Alkermes, NantOmics, Genoptix, Altor BioScience, Merck, Bristol-Myers Squibb, Atreca, Heat Biologics, Leap Therapeutics, RSIP Vision, GlaxoSmithKline

 

Dr. Sandip Patel:

Consulting or Advisory Role: Lilly, Novartis, Bristol-Myers Squibb, AstraZeneca/MedImmune, Nektar, Compugen, Illumina, Amgen, Certis, Eli Lilly, Roche/Genentech, Merck, Pfizer, Tempus, Iovance Biotherapeutics.

Speakers’ Bureau: Merck, Boehringer Ingelheim

Research Funding (Inst.):Rubius, Bristol-Myers Squibb, Pfizer, Roche/Genentech, Amgen

AstraZenece/MedImmune, Fate, Merck, Iovance, Takeda

 

Dr. Michael Zervos:

No relationships to disclose

Doctors James Ferriss, Linda Duska, and Jayanthi Lea discuss the promise and the challenges of targeting the immune system with immune checkpoint inhibitors, or ICIs, in cervical and endometrial cancers. They also examine emerging data that support the use of ICIs in recurrent cervical cancer, the potential for curing some patients with advanced endometrial cancer, and molecular factors that make cervical cancer a good target for immunotherapy.

TRANSCRIPT

Dr. James Stuart Ferriss: Hello, and welcome to the ASCO Daily News Podcast. I'm Dr. James Stuart Ferriss, your guest host of the ASCO Daily News Podcast today. I'm an associate professor of gynecology and obstetrics and the Gynecologic Oncology Fellowship Program Director at Johns Hopkins Medicine. In today’s episode, we'll be discussing the use of immunotherapy in cervical and endometrial cancers to advance the treatment of these malignancies. I'm delighted to be joined by two acclaimed experts in this space, Dr. Linda Duska and Dr. Jaya Lea.  

Dr. Duska is a professor of obstetrics and gynecology and serves as the associate dean for clinical research at the University of Virginia School of Medicine. Dr. Lea is a professor of obstetrics and gynecology and chief of gynecologic oncology at the University of Texas Southwestern Medical Center. 

Our full disclosures are available in the transcript of this episode, and disclosures related to all episodes of the podcast are available at asco.org/DNpod. Drs. Duska and Dr. Lea, it's great to have you on the podcast today. 

Dr. Linda Duska: Thanks, Dr. Ferriss. 

Dr. Jayanthi Lea: Thanks, Dr. Ferriss. 

Dr. James Stuart Ferriss: So, let's get started. In recent years, we've had a revolution in the treatment of advanced endometrial and cervical cancers with improved outcomes for patients treated with immunotherapy. And when we say immunotherapy, we're specifically talking about immune checkpoint inhibitors today. A few of these agents have actually been approved in the United States for the management of these diseases. In our discussion, I'd like to review the promise and challenges of targeting the immune system in patients with advanced endometrial and cervical cancers, as well as review the most recent evidence we have in these spaces. 

Let's start with cervix. We've had a lot of improvements in outcomes here, Dr. Lea, and with cervical cancer, we've seen improved overall survival with the incorporation of immunotherapy along with chemotherapy and anti-angiogenic therapy for advanced and recurrent disease. Can you remind us why cervical cancer is a good target for immunotherapy? 

Dr. Jayanthi Lea: Yes, Dr. Ferriss. Immunotherapy for cervical cancer is supported by several molecular factors. And I think first and foremost, it's so important to remember that the majority of cervical cancers are HPV-positive. And HPV-positive cancers can induce a high level of inflammation, but this high level of inflammation actually contributes to evasion of immune surveillance. What it also does is that it’s responsible for the induction of PD-L1. And we've seen several studies that have shown that cervical cancers express PD-L1 anywhere from 50 to 90 percent of cases. Other pertinent factors to consider are that cervical cancer can be considered a tumor with a high tumor mutational burden. So, the number of somatic mutations that we see in the DNA can be considered as a proxy for neoantigens. And so the higher the level of neoantigens, the more immunogenic the tumor. And then lastly, about 1 in 10 cervical cancers present with microsatellite instability, which is an already established key biomarker for the response team in care. 

Dr. James Stuart Ferriss: So, thinking about targeting PD-L1, what clinical evidence do we have that supports the use of immune checkpoint inhibitors in recurrent cervical cancer? 

Dr. Jayanthi Lea: We now have several studies that have shown a benefit for immune checkpoint inhibitors. For example, KEYNOTE-158 was a phase 2 basket [trial] that investigated the antitumor activity of pembrolizumab, which is a PD-1 inhibitor, in multiple cancer types. And specifically for patients with previously treated advanced cervical cancer, we were able to see an overall response rate of about 15% in those patients who had PD-L1 positive. And similarly, the EMPOWER CERVICAL-1 study, which was a phase 3 randomized trial that investigated the efficacy of cemiplimab, which is another PD-1 inhibitor, versus investigator's choice of single agent chemotherapy, showed a significant difference in median overall survival and progression-free survival in the cemiplimab group. There are several other studies that have investigated the efficacy of PD-1 or PD-L1 inhibitors in cervical cancer. One specific PD-1 inhibitor is nivolumab. In CHECKMATE-358, nivolumab was associated with an overall response rate of 26% in women who had recurrent/metastatic cervical cancer. 

Dr. James Stuart Ferriss: Dr. Duska, do you have any thoughts? 

Dr. Linda Duska: I'm really interested in PD-L1 as a biomarker because in the KEYNOTE-A18 study, which we’re going to get to, 95% of patients were PD-L1 positive by CPS, which is the scoring system that we use in cervix cancer. And some of the studies that you already mentioned, including BEATcc, which we’re also going to talk about, reported results where PD-L1 wasn’t even considered. And so it begs the question, since PD-L1 is actually – again, depending on when in the course of disease you look at it, but more recent studies suggest 95% of cervical cancers express PD-L1, and – agnostic is the word I was looking for – it seems at least in BEATcc and similar trials that PD-L1 is agnostic, but I wonder if PD-L1 is really a good biomarker for response to checkpoint inhibitor therapy and I wonder what your thoughts are. 

Dr. Jayanthi Lea: I think that's an excellent question. To your point, that's correct that we saw in KEYNOTE-A18 that more than 90% of the patients had PD-L1 positivity and the result is sort of generalizable to all comers. That's still a matter of debate as to how we see PD-L1 as a biomarker to incorporate checkpoint inhibitors in the treatment of patients. 

Dr. James Stuart Ferriss: So, let's talk about the use of immune checkpoint inhibitors in the frontline setting. Until recently, we haven't seen much improvement in overall survival since the introduction of anti-angiogenic therapy to the chemotherapy backbone, and that was in GOG 240. Let's talk about the changes that have recently occurred in this space. 

Dr. Jayanthi Lea: So, we've had some very exciting data specifically from initially KEYNOTE-826 and its primary metastatic or first line salvage settings. So, KEYNOTE-826, which was a phase 3 randomized, controlled trial was very practice-changing for us because it showed that incorporation of pembrolizumab to the first-line treatment of patients with metastatic or recurrent cervical cancer, really changed the landscape for treatment in this group of patients. So, keep in mind that prior to the study, the standard of care was carboplatin, or cisplatin with paclitaxel plus or minus bevacizumab, which yielded a median overall survival range in anywhere from 13 to 17 months depending on whether you use bevacizumab or not. And then adding pembrolizumab to that regimen, increase the median overall survival to 24 months, which is very promising. 

Dr. James Stuart Ferriss: If I remember correctly, KEYNOTE-826 allowed investigators choice, use of bevacizumab, and initially we were unsure about which regimen was best. Has there been additional data since? 

Dr. Jayanthi Lea: There has been additional data since. And another study that was done in the same vein was the BEATcc trial, which also looked at the different checkpoint inhibitors, atezolizumab in combination now with bevacizumab and platinum-based chemotherapy. And the control arm for this study was the GOG 240 regimen, which included bevacizumab. And this study showed both a progression-free and overall survival difference. The median overall survival in this study was 32 months with the incorporation of the checkpoint inhibitor to the bevacizumab and platinum-based chemotherapy. So, the way that I look at it is that the BEATcc trial basically confirmed the findings of KEYNOTE-826 and highlights that it is important for us to incorporate checkpoint inhibition with immunotherapy along with bevacizumab when we’re treating patients with a recurrence. 

Dr. James Stuart Ferriss: Also, folks with primary advanced treatment for cervical cancer, this would be a great regimen, is that right? 

Dr. Jayanthi Lea: Absolutely. Primary advance, we would want to use the same regimen for that. 

Dr. James Stuart Ferriss: Okay. What about locally advanced in primary treatment? What advances have we seen? 

Dr. Jayanthi Lea: So we've had some major changes in that field as well, especially with the recent KEYNOTE-A18 data where pembrolizumab was administered in combination with external beam radiation and concurrent chemotherapy. And this study showed that there was significant and clinically meaningful improvement in progression-free survival compared to chemoradiation alone. Specifically, the progression-free survival at 24 months using pembrolizumab with chemoradiation was 68%, and 57% when in the placebo group. The hazard ratio for disease progression was 0.7 and no new safety signals were observed, which is fantastic, especially given the 0.7 hazard ratio that received PFS. 

Dr. James Stuart Ferriss: Yeah, absolutely. These patients with locally advanced cervical cancer often are quite symptomatic, and the prospect of adding chemo, radiation, and now immunotherapy on top of that is really encouraging to see that it was such a well-tolerated regimen. I believe that there were patient-reported outcomes recently reported at SGO. 

Dr. Jayanthi Lea: Absolutely. So, the safety profile of pembrolizumab and chemoradiation was consistent with the known profile of the individual treatment components. And no new safety signals emerged in the pembrolizumab chemoradiation arm. So, you’re right. It was very well tolerated. 

Dr. James Stuart Ferriss: What would you say are the takeaways for folks who are seeing these patients in the community? These locally advanced cervical cancer patients that are now adding immunotherapy in a space that we have not used routinely in the past in terms of combining it with chemo radiation in gynecologic cancer. What are some things they should be looking out for? 

Dr. Jayanthi Lea: Well, I think that with the hazard ratio of 0.7 and the patient-reported outcomes showing no new signal, I think we can say that there is a positive benefit-to-risk profile of adding pembrolizumab in combination with chemoradiation, and that we should feel comfortable using this regimen. Now, of course, we have individualized patient care, and be able to know when to use bevacizumab, when to use immunotherapy. So, taking the whole patient into consideration becomes important. But for those individuals who are able to receive these drugs who don’t have concrete issues to not receive these drugs [then I’d say we could] incorporate them since the safety profile is set. 

Dr. Linda Duska: I would add to that, Dr. Ferriss, that right now we only have FDA approval in the U.S. for stage 3-4A disease, and that’s 2014 staging. Mind you, we are now in 2018, so we should be very careful in and follow the correct FIGO staging. But the FDA only gave approval for stage 3-4A disease, even though the study included patients with earlier stage disease and positive nodes. 

Dr. James Stuart Ferriss: That's a great point, thank you. 

So, Dr. Duska, thinking about endometrial cancer and advanced endometrial cancer, we have seen a similar revolution in the care of patients over the past few years, with major shifts in our approach. Can you remind us how we got here? 

Dr. Linda Duska: Yes, I would say in the ‘90s and before, and maybe even in the early 2000s, we used a lot of radiation for endometrial cancer as adjuvant therapy following surgery. The general consensus and what we were all taught was that this was a chemotherapy-resistant disease. And then we learned from a variety of GOG at the time, Gynecologic Oncology Group trials, that this disease is actually chemosensitive. And we went through a series of chemotherapy drugs, ranging from adriamycin cisplatin to taxel adriamycin cisplatin, and finally to taxel and carboplatin, demonstrating that this disease is actually quite chemosensitive. 

With this realization came the idea that maybe it would be important to combine chemotherapy and radiation particularly in high-risk endometrial cancer cases, so those with positive nodes or patients with high-risk histology such as clear cell or serous cancers. So two very important trials were done, one of them was PORTEC-3 and the other was GOG-258, which looked at combining chemo and radiation together to see if we could do better than one or the other alone. And they were very different trials, and they looked at different populations of patients and they looked at different things. For example, PORTEC-3 randomized patients to receive chemotherapy and radiation versus radiation alone, while 258 looked at chemotherapy and radiation versus chemotherapy alone. Without going into a great amount of detail, I think what we learned from both of those studies, and I think surprised many of us, that the arms that included chemotherapy, those patients did better. 

In fact, the results of GOG-258 can be interpreted – and this is somewhat controversial – but can be interpreted that many of these high-risk patients don’t need radiation at all, or perhaps need tumor-directed radiation. For example, chemotherapy followed by tumor-directed radiation either to the vaginal cuff, because the vaginal cuff is at risk for recurrence, or perhaps to an area of concern, maybe the cervix if there were cervical involvement or if there is a particular concern for local recurrence in a particular patient. So, I think the pendulum has swung from almost always using radiation alone to, in more modern day, using chemotherapy and using radiation much more sparingly, and then comes immunotherapy. 

Dr. James Stuart Ferriss: So, update us on the results of NRG-GY018 and RUBY? 

Dr. Linda Duska: So, we've already talked about the KEYNOTE basket trials, which really contributed a lot to our understanding of the importance of MMR deficiency and microsatellite unstable disease. The KEYNOTE-158 study and the GARNET study showed us how important it was for women with MMRd and MSI endometrial cancer to receive checkpoint inhibition, and actually with remarkable response rates to women who had already been pretreated. But we also learned from the GARNET trial, which included MMRp patients, that the response rates in MMRp were not that great. And that led to KEYNOTE-775, which looked to combine pembrolizumab with a VEGF inhibitor, lenvantinib, to see if we could make the cold tumor hot. And indeed, we could. And not only could we improve the response rate in patients with MMRp tumors, but we could also improve the response rate in patients with MMRd tumors. They did better with the combination than they did with pembro alone. 

That led to the idea of combining checkpoint inhibitors with chemo upfront. The idea there was we were going to take paclitaxel and carboplatin, which were our backbone for advanced or recurrent endometrial cancer, and add immunotherapy to that. And to your point, GY018 and RUBY trials did just that. And they allowed MMRd and MMRp patients and combined paclitaxel and carboplatin, either with dostarlimab in the case of RUBY, or pembrolizumab in the case of GY018. These studies, both of which were reported and published in the New England Journal of Medicine last year, showed remarkable findings in the upfront setting and potentially in the curable setting. And the OS data for RUBY were presented at SGO this year and were remarkable for MMRd patients. In the whole population, in the whole group in RUBY, there was a 16.4-month improvement in overall survival with the addition of dostarlimab which is just huge. 

When you look at the MMRd group, I think Dr. Powell described the overall survival improvement as unprecedented. I believe that was the word that he used. Also, he called it very robust, with a hazard ratio of 0.32 for the group that got dostarlimab, and a median OS that was not reached. So really remarkable. In addition, in the MMRp group, there was a seven-month improvement in OS that was significant. So that's really amazing in the RUBY trial. It's also of note that the RUBY trial allowed carcinosarcomas, whereas the GY018 study did not. So, I think it's fair to say that these results apply to carcinosarcomas. 

It's also really important to note that many of the patients in the immunotherapy group who received placebo, 41% of them got IO in a later treatment line, and these OS data still stand. So that's really interesting and hypothesis-generating. For GY018, we don't have mature OS data yet, so we can't talk about OS. But we saw a similar improvement in PFS in both arms, in the d and the pMMR, with an OS trend in both arms that was also reported at SGO. GY018 was a little bit different though, because they unblinded at the time of the PFS reporting last year, and so those patients were unblinded a lot earlier than the RUBY patients were. So, to interpret the data in that vein, the OS data is not mature, but we anticipate looking at the PFS curves and the preliminary OS curves, that the OS data will also be statistically significantly improved in core pembrolizumab in GY018. 

What's also really interesting, and we haven't talked about molecular subtypes, is that when we look at the molecular subtypes in RUBY, and I'm sure we're going to see data on the molecular subtypes in GY018 coming up, different molecular subtypes of endometrial cancer respond differently to IO. And so, there's going to be lots of really interesting data coming our way soon that we're really excited to see, and that will help us triage patients appropriately into treatment regimens. 

Dr. James Stuart Ferriss: Dr. Lea, did you have a thought? 

Dr. Jayanthi Lea: Yeah, I just wanted to comment that looking at the dMMR survival curve in the file that was presented recently, one thing that really strikes me is the importance of adding the IO at the time of initial treatment. The separation of the curves persists. And, like you just mentioned, Dr. Duska, I mean, some of those patients who received placebo then later on went to get an IO treatment, but at the same time, we still see a vast separation of those curves. So, I think it's really important to note that immunotherapy should be used upfront, especially in dMMR. 

Dr. Linda Duska: Yeah, I completely agree with that. And I think that might be– I mean, this is just a hypothesis, but I think that that might be why we saw a difference with the addition of immunotherapy in the MMRp group, because it's possible that the chemotherapy created an immune environment that made the checkpoint inhibitor work more successfully than it would have otherwise. So, a really good point. You definitely need to include dostarlimab or pembrolizumab with the chemotherapy and then as maintenance therapy after. 

Dr. James Stuart Ferriss: So, you mentioned, we're increasingly thinking about endometrial cancer in smaller and smaller buckets of patients with very prescribed molecular profiles. We don't yet have enough information to specifically tailor treatment. How are you approaching that today in patients that you see in clinic? 

Dr. Linda Duska: Well, the MMR, and I'm interested in what you both are doing also, it's easy with the MMRd and MSI high patients. Those patients all should receive a checkpoint inhibitor, no question. The patients that are p53 mut, I test them for HER2, because we do have data to suggest that atezolizumab or TDX-d might be useful in those individuals, HER2 positive. And then the remaining patients, also called the NSMPs. That's a difficult group. I'm interested to know how you all manage them. I think that's the group where more clinical research is really needed to determine what the best treatment regimen for them is. But I'm interested in both of your thoughts on that. 

Dr. James Stuart Ferriss: Dr. Lea? 

Dr. Jayanthi Lea: I would have to say that I do exactly like you do, Dr. Duska. 

Dr. James Stuart Ferriss: And I would say our approach is very similar. And we have a robust discussion always about the use of immunotherapy with chemotherapy and in patients who are proficient MMR. But I think that most of us believe that the PFS data is certainly compelling. And now the OS data from RUBY, very compelling in both groups. And so, we are routinely recommending the use of immunotherapy along with chemotherapy in these advanced patients. 

Dr. Linda Duska: I've heard the argument made that GY018 required measurable disease, and so does not necessarily apply to patients without measurable disease. I'm not sure that I agree with that. I think there were clinical trial reasons why that was a requirement rather than biologic reasons. In addition, as we already discussed, RUBY included carcinosarcomas and GY018 did not. I don't think there's a reason to only use dostarlimab for carcinosarcomas, but that said, I don't know that pembrolizumab has an indication for carcinosarcomas. The devil's in the details, don't get too lost in the weeds. I think the take-home message here is that it's really important to use IO, particularly for the MMRd patients with endometrial cancer, upfront. And based on the OS that we saw in both RUBY and preliminarily in GY018, we may be curing some people with this regimen, and I think we should focus on that. The overall survival for advanced endometrial cancer is not great, and if we can improve that and potentially cure some people, that's a huge advance for our patients. 

Dr. James Stuart Ferriss: Do you envision a day that we might even ask the question, “Do we need to do surgery?” 

Dr. Linda Duska: So, the rectal data would support that assertion. I'm not sure that endometrial cancer and rectal cancer are the same thing. And I think that taking out a postmenopausal woman's uterus is a lot less morbid than potentially radiating or taking out somebody's rectum. I think a different question would be, is there a day when we would stop doing no dissection? We could definitely debate that, but I don't see that happening. Do you see that happening anytime soon? A stopping of hysterectomy for endometrial cancer?

Dr. Jayanthi Lea: I don't see that happening anytime soon. And I think, as you said, taking out the uterus, tubes, and ovaries, it does provide us with some information about whether you're even dealing with a secondary primary. But also, it’s from a quality-of-life standpoint. If a woman has a large uterus, that’s uncomfortable. Postmenopausal bleeding, avoiding bleeding during the course of treatment, so many reasons why I wouldn't be in too much of a hurry to want to not do surgery for these patients.

Dr. James Stuart Ferriss: So, we'll put a plug in for our fellow gynecologic oncologists that we still have a role to play in the incorporation of treatment regimens for patients with advanced uterine cancer. So it's not just medicine, there's still a role for surgery. 

Dr. Linda Duska: I think that's very fair, yeah.

Dr. James Stuart Ferriss: Okay. I think that's all the time we have for today. 

I want to thank our listeners for their time, and you'll find the links to all the studies we've discussed today in the transcript of this episode. And finally, if you value the insights that you hear on the ASCO Daily News Podcast, please take a moment to rate, review, and subscribe wherever you get your podcasts. Thank you. 

Dr. Linda Duska: Thank you.

Dr. Jayanthi Lea: Thank you.

Disclaimer: The purpose of this podcast is to educate and to inform. This is not a substitute for professional medical care, and is not intended for use in the diagnosis or treatment of individual conditions. Guests on this podcast express their own opinions, experience, and conclusions. Guest statements on the podcast do not express the opinions of ASCO. The mention of any product, service, organization, activity, or therapy should not be construed as an ASCO endorsement.

  

Find out more about today’s speakers:

Dr. James Stuart Ferriss

Dr. Linda Duska

@LDuska

Dr. Jayanthi Lea

 

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Disclosures:

Dr. James Stuart Ferriss:

Honoraria: National Board of Medical Examiners

Dr. Linda Duska:

Consulting or Advisory Role: Regeneron, Inovio Pharmaceuticals, Merck, Ellipses Pharma

Researching Funding (Inst): GlaxoSmithKline, Millenium, Bristol-Myers Squibb, Aeterna Zentaris, Novartis, Abbvie, Tesaro, Cerulean Pharma, Aduro Biotech, Advaxis, Syndax, Pfizer, Merck, Genentech/Roche, Cerulean Pharma, Ludwig Institute for Cancer Research, Leap Therapeutics

Patents, Royalties, Other Intellectual Property: UpToDate, Editor, British Journal of Ob/Gyn

Dr. Jayanthi Lea:

Consulting or Advisory Role: Roche

Drs. Shaalan Beg and Aparna Parikh discuss the role of ctDNA as a powerful prognostic biomarker for GI cancers, along with its impact on risk stratification and the detection of recurrence. They highlight key studies in ctDNA that were featured at the 2024 ASCO GI Cancers Symposium, including COBRA, GALAXY, and BESPOKE in CRC, as well as the promise of ctDNA testing in the preoperative detection of iCCA.

TRANSCRIPT

Dr. Shaalan Beg: Hello, and welcome to the ASCO Daily News Podcast. I am Dr. Shaalan Beg, your guest host for the ASCO Daily News Podcast today. I am an adjunct associate professor at UT Southwestern's Harold Simmons Comprehensive Cancer Center in Dallas. On today's episode, we will be discussing the emergence of circulating tumor DNA (ctDNA) technology in GI cancers. I am delighted to be joined by Dr. Aparna Parikh, an assistant professor of medicine at Harvard University and the director for colorectal medical oncology at the Massachusetts General Hospital Cancer Center, where she also serves as the medical director of the Young Adult Colorectal Cancer Center. Dr. Parikh will share her insights on key research on this hot topic in GI oncology that was featured at the recent ASCO Gastrointestinal Cancers Symposium. 

Our full disclosures are available in the transcripts of this episode, and disclosures related to all episodes of the podcast are available at asco.org/DNpod. 

Dr. Parikh, it's great to have you on the podcast today.

Dr. Aparna Parikh: Thanks so much, Dr. Beg. 

Dr. Shaalan Beg: In recent years, it has become evident that liquid biopsy and other emerging ctDNA technologies are changing how we treat GI cancers, and colorectal cancer (CRC) is in the forefront of this space. Before we dive into key studies, can you briefly highlight for our listeners how ctDNA is advancing the field and how it can influence the care that we deliver to our patients in the future?

Dr. Aparna Parikh: Absolutely, ctDNA is certainly a hot topic. What we have learned over the years is that ctDNA has emerged across many solid tumor types as one of the most powerful, if not the most powerful, prognostic biomarker we have to date. ctDNA has improved risk stratification. We have learned a lot about the role in what is called minimal or molecular residual disease in patients with early-stage disease, and ctDNA being a biomarker of recurrence for those patients, with ctDNA, we have a better understanding of tumoral heterogeneity, both spatially and temporally, getting a better glimpse of what is happening in a given patient with multiple metastases, as well as genomic evolution of tumors over time. So certainly many, many roles and areas where ctDNA is emerging.

Dr. Shaalan Beg: This was a hot topic at the 2024 ASCO GI Cancers Symposium, and we're going to take a deep dive into some of the abstracts that were presented. Let's start with the COBRA study, which is the NRG-GI005. That was Abstract 5 at the ASCO GI Cancers Symposium, and the GALAXY study, which was Abstract 6 at the symposium. So, the COBRA study reported results of ctDNA as a predictive biomarker in adjuvant chemotherapy for people with colon cancer. At a high level, it was a negative study, but there are some important lessons for us to learn. Similarly, in the GALAXY study, investigators from Japan presented an updated analysis on the correlation of ctDNA dynamics with outcomes in colorectal cancer with minimal residual disease. How do you synthesize all this information and help the listeners understand our current state for ctDNA applications in colorectal cancer?

Dr. Aparna Parikh: Yeah. Let's take the COBRA study first. Let's talk a little bit about the design of COBRA. COBRA was intended to look at patients that were resected, stage 2 colorectal cancer patients, or colon cancer patients who were 2A. These are patients where the treating physician would, at the outset, decide that there was no adjuvant chemotherapy indicated. These are patients where active surveillance would be entirely appropriate as the standard of care. Patients were randomized to arm 1, which was active surveillance, or randomized to arm 2, which was assay-directed therapy. If there were ctDNA positive in arm 2, then they were given chemotherapy, FOLFOX or CAPOX. And if they were “ctDNA not detected,” then they would also go on to active surveillance.  

And so, the plan was that nearly 1,500 patients are to be recruited, and at the time of this data cut, they had around 630-some patients. The primary objective was to look at the clearance rates of ctDNA between the ctDNA-positive cohorts, remember, the chemotherapy and the active surveillance cohorts at 6 months. They had around a 5% detection rate of ctDNA patients. Ultimately, that was around 16 patients. The reason that the study shut down was that what they found was that in the surveillance arm, the arm that was not getting any treatment, they had a ctDNA clearance of 43% versus 11% in the chemotherapy arm. They had an interim analysis to look at the clearance rate between the 2 arms, and what was surprising to the investigators and the community was what was happening in terms of clearance. Why do we have a 43% clearance rate in patients that were not getting anything? And so, because of that, the study was shut down as it did not meet its prespecified interim look at clearance in those 2 arms.  

Many things came up in terms of learnings from COBRA. Number one was the characteristics of the assay. And so, you take an assay in a low-risk patient population that has a fixed specificity, and when your baseline prevalence of recurrence is so low, for example, in low-risk stage 2 patients, your composite predictive value is very susceptible to small changes in that specificity. And so, your PPV is going to be a lot lower in a low-risk patient population than a higher-risk patient population. The COBRA study used an older version of a tumor-uninformed assay, so it definitely called into question some characteristics of the assay. Is one-time-point clearance sufficient, and is that the right endpoint? We have seen now, including the GALAXY study that we'll talk about here, previously reported just spontaneous clearance happening in 5%, 10% of patients. The question with that spontaneous clearance is: Was it actually clearance, or was chemotherapy just perhaps in a low ctDNA shedding state? Are you just suppressing the ctDNA below the level of limited detection? 

And then in this study, the clearance draw was actually done in the chemotherapy arm right before the last cycle of chemotherapy, again to that point of, are you just suppressing the ctDNA with chemotherapy? There is also stochastic sampling error that can happen in patients with very low residual tumor volume. So, I think this is a disappointing study in the sense that it is still a really important question. There are still 2A patients that recur, but maybe [this was] not the right test, or maybe single-time-point testing wasn't enough. And so, lots of lessons to be learned from this study in terms of test and design, but hopefully more to come. I think certainly stage 2 patients remain an area where I think, hopefully, ctDNA still plays a factor for those patients. 

Dr. Shaalan Beg: And how was the patient population for the GALAXY study? That was Abstract 6, compared to the COBRA study. Could you summarize those findings for us? 

Dr. Aparna Parikh: Yeah, so GALAXY was part of a large study in Japan that includes an observational cohort plus therapeutic cohorts as well. And so, GALAXY was just further reporting of the observational cohort. So unlike COBRA, which is a low-risk, stage 2 study that was actually asking that interventional question: Can you use it to guide therapy? The GALAXY and the updated GALAXY just continues to show more clinical validity data rather than clinical utility data. And it was nearly 3,000 patients, pan stages. Again, the lion’s share were stage 2 and 3 patients, but there were also stage 1 and stage 4 patients as well. And what they showed was that ctDNA is undoubtedly prognostic. They showed very consistent Kaplan-Meier curves, which we've seen time and time again, where if you're ctDNA-positive, you don't do as well. 

What they showed was, not surprisingly, with longer-term follow-up – this is 24-month follow up, so longer-term follow up than was published in their paper last year – was that when you test at one time point, so landmark testing, the sensitivity of detecting recurrence was around 48%, and that fell from the publication last year which was around 58%, 59%, which is not surprising as you follow more people. I think single time point testing soon after surgery may miss those late recurrences, but it's still prognostic and showed a specificity of around 94%.  

They also continued to show that if you continued to test with serial testing, your sensitivity improves, but what was really interesting and new, what they presented this time, was a clearance analysis. And showing, again, comparable to COBRA, in many ways, in the sense that clearance can be a little bit finicky, especially at one time point, is what they showed is that patients who had sustained clearance, and these are patients that had at least two time points with their ctDNA remained to be negative, they did very well. But if you had transient clearance, and again, the definition was a little bit broad, at least having one negative and then one positive, those patients ultimately, at 24 months, the curves came together with the no clearance curve. So initially, they did better than the people that didn’t have any clearance. But if you transiently cleared at two years, the curves came back together.  

And what was interesting is that in those patients that sort of transiently clear by 9 to 12 months, 80% of those are actually having a rapid return of ctDNA. And so this begs the question of was chemotherapy just suppressing that ctDNA or maybe if you have a better test you could have actually improved it. 

These were some of the updated, interesting learnings from GALAXY, which remains incredibly prognostic. And then the concept of clearance, which I think we have to look into a little bit more as a field, and understanding that maybe just one time point clearance isn't sufficient. 

Dr. Shaalan Beg: Yeah, and one of the most important applications for ctDNA can be its ability to inform adjuvant chemotherapy. Its ability to not only identify more people who may benefit from chemotherapy, but maybe even identify people who don't need chemotherapy. And along those lines, Abstract 9, the BESPOKE study, looked to understand the role of ctDNA-based detection of molecular residual disease to inform adjuvant therapy for stage 2 and 3 colorectal cancer. And they presented interim data at the GI ASCO this year. What were your takeaways from this study?

Dr. Aparna Parikh: Exactly. Beyond the prognostic implications, I think what was really interesting was that there was the initial data looking at the benefit of adjuvant chemotherapy. So, what they did was they said, “Okay. We’re going to take the MRD-positive patients and look at the benefit of adjuvant chemotherapy and then the benefit of adjuvant chemotherapy in the MRD-negative patients.” And again, remember, this is a prospective observational study, so it's not looking at negative and positive to guide therapy, but it's just looking prospectively and observationally at how those patients are doing. But what they showed again is that indeed, in the adjuvant chemotherapy group, the benefit of adjuvant chemotherapy again with the follow-up to date on the study was different in the MRD-positive patients. 

First of all, I guess taking a step back, the DFS in the ctDNA-negative patients at 2 years was very good. So negative patients had over 98% 2-year DFS in both the adjuvant chemotherapy and observational group. And there was no real difference between adjuvant or not. But in the positive patients, not surprisingly, the DFS was worse. But what was reassuring to see is that you can make an impact with adjuvant chemotherapy in the positive patients. And the difference in DFS between the positive and negative patients, with adjuvant or not, was 42% versus 12.5%, in the observational patients. So, it is benefitting the patients who are positive so it does give us more data that, again, at least in the positive patients, you may be able to reverse the recurrences there with adjuvant chemotherapy. And maybe if you’re negative, eventually, we'll get to a point of de-escalation of care. Again, keeping in mind the kinds of sensitivity limitations as well. 

Dr. Shaalan Beg: Wonderful. And one of the other malignancies in the GI space where precision therapies and molecular biomarkers are making a huge difference are intrahepatic cholangiocarcinoma. Genomic profiling using ctDNA is increasingly being used in this population to inform precision oncology approaches and determine mechanisms of resistance to targeted therapies as well. In Abstract 528, investigators looked at the role of preoperative ctDNA testing for resectable intrahepatic cholangiocarcinoma. What are your thoughts on that study? 

Dr. Aparna Parikh: Yeah, it's such an important area, as you mentioned, in the metastatic space – FGFR, IDH1, all these alterations that are emerging in intrahepatic cholangios. This was a very small study, it was preoperative, and so the tumor was intact, and around 14 patients. They used a tumor-informed approach just for detection and quantification of ctDNA. So this was not a study that was looking at a next-generation sequencing approach where you’re going to actually be able to detect the alterations, but it’s actually looking for the detection and quantification of ctDNA rather than genomic characterizations. And patients had about a month or so where they had their baseline blood detected.

And I think what was reassuring to say was that ctDNA was actually detected in all the patients with the primary tumor intact, except for one patient who was a very low-risk stage 1A patient. There was some correlation, against a small number of patients, between the concentration of ctDNA in patients that had the lower stage and then the higher stage groups. Small numbers were actually hard to characterize and correlate with recurrence or mortality, but at least, some correlation with pathologic tumor size, they were able to because it was a bespoke panel and you’re sampling the tissue and then looking in the blood, IDH1 and 2 were mutations that were tracked based on the genomic profiling and a couple of the patients were able to have their IDH mutations tracked. 

So it gives us a sense, a little bit, that ctDNA, we know has a lot of variable shedding across disease states and tumor locations, but gives us some promise that it is reliably detected with the tumor-informed approach, at least preoperatively in cholangios. So may again open some more opportunities for MRD testing in cholangiocarcinoma as well. 

Dr. Shaalan Beg: Thank you. That's a wonderful review of ctDNA applications in gastrointestinal cancers from the 2024 ASCO GI Cancers Symposium. Thank you, Dr. Parikh, for sharing your valuable insights with us on the podcast today.

Dr. Aparna Parikh: Thank you so much for having me.

Dr. Shaalan Beg: Thank you to our listeners for your time today. You'll find links to the abstracts discussed today in the transcript of this episode. Finally, if you value the insights that you hear on the ASCO Daily News Podcast, please take a moment to rate, review, and subscribe wherever you get your podcasts.

 

Disclaimer:

The purpose of this podcast is to educate and to inform. This is not a substitute for professional medical care and is not intended for use in the diagnosis or treatment of individual conditions. Guests on this podcast express their own opinions, experience, and conclusions. Guest statements on the podcast do not express the opinions of ASCO. The mention of any product, service, organization, activity, or therapy should not be construed as an ASCO endorsement.

 

Find out more about today’s speakers:

Dr. Shaalan Beg

@ShaalanBeg

Dr. Aparna Parikh

@aparna1024

 

Follow ASCO on social media: 

@ASCO on Twitter 

ASCO on Facebook 

ASCO on LinkedIn 

 

Disclosures:

Dr. Shaalan Beg:

Employment: Science 37

Consulting or Advisory Role: Ipsen, Array BioPharma, AstraZeneca/MedImmune, Cancer Commons, Legend Biotech, Foundation Medicine

Research Funding (Inst.): Bristol-Myers Squibb, AstraZeneca/MedImmune, Merck Serono, Five Prime Therapeutics, MedImmune, Genentech, Immunesensor, Tolero Pharmaceuticals

 

Dr. Aparna Parikh:

Consulting or Advisory Role (An Immediate Family Member): PMV

Consulting or Advisory Role: Checkmate Pharmaceuticals, Guardant Health, Foundation Medicine, Abbvie, Value Analytics Labs, Bayer, Taiho Oncology, Delcath, Seagen, CVS, SAGA Diagnostics, Scarce, Illumina, UpToDate, Takeda, AstraZeneca, Takeda, Pfizer, Kahr, Xilio Therapeutics, Sirtex

Research Funding: PMV Pharma, Erasca, Inc, Syndax

Research Funding (Institution): Bristol-Myers Squibb, Genentech, Guardant Health, Array, Eli Lilly, Novartis Pharmaceuticals UK Ltd., PureTech, Mirati Therapeutics, Daiichi Sankyo, Karkinos

Other Relationship: C2i Genomics, Xgenomes, Parithera, Cadex

Drs. Shaalan Beg and Travis Osterman discuss a machine learning model, recently featured in JCO Clinical Cancer Informatics, that uses electronic health record data to accurately predict the effectiveness and toxicity of treatment with immune checkpoint inhibitors. The new AI model can be used to provide a personalized risk-benefit profile, inform therapeutic decision-making, and improve clinical trial cohort selection.

 

TRANSCRIPT

Dr. Shaalan Beg: Hello, and welcome to the ASCO Daily News Podcast. I'm Dr. Shaalan Beg, your guest host for today. I am an adjunct associate professor at UT Southwestern's Simmons Comprehensive Cancer Center. 

Cancer immunotherapy has transformed the treatment landscape by providing new and effective treatment options for many solid and hematologic malignancies. But while many patients experience a remarkable response to immune checkpoint inhibitors, other patients can suffer life-threatening immune checkpoint toxicities. Today, we will be discussing a machine learning solution that can assess a patient's immune checkpoint inhibitor risk-benefit profile based primarily on routinely collected structured electronic health record data. This novel AI solution was recently featured in JCO Clinical Cancer Informatics, and I am delighted to welcome one of the report's authors, Dr. Travis Osterman. He is an associate vice president for research informatics and associate professor in the Department of Biomedical Informatics and the Division of Hematology Oncology at Vanderbilt University Medical Center in Nashville, Tennessee. Dr. Osterman also serves as the director of cancer clinical informatics at the Vanderbilt Ingram Cancer Center. 

Our full disclosures are available in the transcript of this episode, and disclosures related to all episodes of the podcast are available at asco.org/DNpod. 

Dr. Osterman, it's great to have you on the podcast today.

 

Dr. Travis Osterman: Thanks, Shaalan. It's great to be here. Thank you for the invitation.

 

Dr. Shaalan Beg: Congratulations on your recently published article in the JCO CCI titled "Prediction of Effectiveness and Toxicities of Immune Checkpoint Inhibitors Using Real World Patient Data." Why did you decide to address this specific problem?

 

Dr. Travis Osterman: I am a practicing medical oncologist at Vanderbilt, I specialize in thoracic malignancies. Immunotherapy has been a significant part of my practice from the beginning. And I think for all of us, we have patients in our practices that are tremendous responders. I have stories of my patients, a few of which, at least, are able to get years of benefit even after stopping therapy, and potentially some even stage 4 patients that are amazingly seemingly cured after their treatments. But I also have patients that experience severe toxicities, some of those are life-threatening or life ending, but many of those carry morbidity. In my population, I see a lot of pneumonitis, and that really alters patients' quality of life. And the biggest conversation I have with patients is: “How do I know which of these outcomes I’m going to have, if I’m going to get benefits from these therapies or am I going to get one of these side effects or toxicities?” And we set out to try to answer that question with data.

 

Dr. Shaalan Beg: When electronic medical records started to make their way into the clinic, I remember all of us thinking about the wonderful applications where we could use the data to help guide the clinical care, assign the right treatment for the right patient at the right time, and learn from other patients' experiences to improve the care of the person who’s in front of us. And my personal opinion is that we haven’t realized our electronic medical records’ potential to that extent. And efforts like the one you published in JCO CCI is the culmination of one of the efforts, and I can only imagine how much time and effort it must have taken to develop that and we’re hoping is the first of many more to come. For our listeners, can you talk us through the steps required to develop such a tool, and why now is the right time, and why we’re starting to see these evolve?

 

Dr. Travis Osterman: This project would not have been possible 20 years ago. It relies on having what we would call structured data available for our patients that are receiving cancer care, so that’s vital signs, laboratory values, and diagnoses, all of the things that we routinely collect in the electronic health record. So that is step 1. This project required that those systems be not just in place at academic centers but be widely available because our goal is to set up systems that will be able to transform cancer care, not just at academic institutions, but for the entire practice of oncology. 

The second piece is you need enough data to be able to train these models. And so, we needed to be practicing with checkpoint inhibitors long enough to see patients that had toxicities, to see patients that had benefit, and then to jump into the data science of actually trying to learn from them. And so this really was the culmination of systems put in place by a lot of people before us and then really the right time [when] we started to have now enough data to really start to learn from.

 

Dr. Shaalan Beg: The publication discusses the steps of how you validated your tool. Talk me through how you see this being applied to the point of care for the next time you are about to start an immune checkpoint inhibitor for your lung cancer patient?

 

Dr. Travis Osterman: I think there are two different primary lanes that these types of models can be applied. In the drug development space, I think many of us are familiar that many assets, many drugs that are in the development pipeline are halted because of adverse events in toxicity profiles, but we also realize that not everyone gets those toxicities. And so we envision a future where before a drug that's in the drug development pipeline is taken out of the development pipeline, potentially, you could screen patients that are at lowest risks of actually having side effects from that immunotherapy and only screen those patients into the trial and that would potentially make more drugs available to more patients going forward. So I think that that's 1 lane. 

I think the other lane in clinical practice is, let's say that I'm treating a patient who we determine has an increased risk for colitis. Instead of only seeing that patient back in 3 weeks, potentially, now, what if I had one of our nurse navigators, call the patient at weekly check-ins between visits to check in and see whether or not they were having any episodes of diarrhea and trying to intervene earlier. That might allow us to keep patients both out of the hospital, out of the emergency department to treat their symptoms more quickly to decrease the severity of their toxicity and keep them on treatments, especially if they're receiving benefit from it. So, I think there's an opportunity to improve both drug development and making more drugs available to patients and then also to identify patients that are at risk for toxicity, and then to do interventions to help mitigate those risks. Really, the idea of precision risk mitigation.

 

Dr. Shaalan Beg: One of the problems with electronic medical record-based tools in the past has been that they don’t evolve with time. We develop it, we set it, we deploy it, and it almost feels, to the users at least, that it stops evolving after that. With novel therapeutic agents coming into the clinic, we're seeing new ADCs, new novel checkpoint inhibitors entering the market. How do you envision tools such as yours to be refreshed so they can stay relevant with the modern armamentarium of medications which are being used?

 

Dr. Travis Osterman: So, if you ask any data scientist, the most requested item they will ask for is more data. And so, this initial set of models that we've described in this publication were trained exclusively on a single institution's data at Vanderbilt University Medical Center as we continue both to see more patients here, and then ideally look forward to collaborations with other centers. We expect that these models will continue to be refined and that the performance will improve as we increase the amount of training data, and we hope that that will do 2 things. One, it will counteract the kind of model drift that you described. But then two, it will allow us to ask some more specific questions that honestly, we weren't really powered to answer in our study here. For instance, we didn't look at cardiac toxicity, which is a concern if you're giving a CTLA-4 along with a PD-1 or PD-L1 inhibitor more so than single agent immunotherapy. We just don't have enough events to be able to train models on that. But with future collaborations, that would be a question we would love to tackle as well. 

One of the things that's interesting about the implementation of these models is that we found many of the features that I would have expected to find as a practicing oncologist. For instance, when we're trying to predict the toxicity of pneumonitis inflammation of the lung, I as an oncologist would think that many of my patients that have COPD or interstitial lung disease at baseline seem to be at a higher risk. And so that's one of the features that I was looking to come out in the model. And that's exactly what we found. That was one of the contributing features that helps us predict a higher risk of pneumonitis. But what's interesting is that's certainly not the only feature; there end up being about a dozen features that are in that space that help predict that toxicity.  

Similarly, for colitis, we found that the combination of receiving a CTLA-4 inhibitor in addition to a PD-1 or PD-L1 inhibitor, that combination together, which would increase risk for colitis, which is well-documented in our literature. So these models are not entirely black boxes. We've published the top features of these models that contribute to our predictions. And I think clinically the challenge for me has always been if I have a patient who has COPD, but it's pretty well-controlled and their O2 sat is normal, how does that patient's risk bring pneumonitis compared to someone who has poorly controlled COPD with low O2 sat at baseline, etc.? And so these models are really designed to help tease out some of those nuances.

 

Dr. Shaalan Beg: There are so many wonderful applications to use preexisting data that can improve the lives of our patients and frankly that can improve the work experience for clinicians. They can be used for risk stratification using these preexisting data. Can you talk a little bit about what are the barriers that people face or that your team faced in developing these tools, and what has changed or what's expected to change in the coming years to allow people to continue developing tools such as what was described?

 

Dr. Travis Osterman: I think it's important to realize that we are not unique in addressing this problem. This is a problem that I think has been a focal point of our cancer informatics community for the better part of the last, probably, decade. I think one of the things that distinguishes the work that we've done here is really this idea of clinical utility. And what I mean is we focused on data that would be collected at any routine oncology visit in the U.S., and I would argue worldwide, to use as features in our model. So, we're not running complex genetic testing that may or may not be paid for. We're not asking for new laboratory values to be sent or for extensive questionnaires that aren’t already in clinical practice. We're using pieces that are already being connected into the pipeline of oncology practices, and I think that's one of the differentiators of this project versus many others in this space. 

Right now, these are only EHR data. We have a part of our project that's looking at imaging data and whether that adds value. But one of the pieces that I always advocate for, if we're going to ask practices for instance to upload these imaging files or to send a CD to a central location to improve the outcome, that's harder to work into an oncologist workflow than if all the data are already there in the health record and you can click a button and calculate this person's risk profile. And so, we've really tried to be pragmatic about our approach as we've entered this realm and that's been a real focus of our team.

 

Dr. Shaalan Beg: Many of the listeners of today’s podcast are busy clinicians, and you talked about how the idea for this project came from the problem you witnessed in your clinic. How can clinicians continue to be involved in such initiatives or drive these initiatives at their own institutions, in office situations where they may not have the resources that your team has? Can you speak to national efforts or collaborations in this regard?

 

Dr. Travis Osterman: Yeah. So, first of all, I would invite really anyone to reach out to our team, if they're in a position where they'll be interested in validating our models at their local institutions. We would be happy to work with them to provide the models to see how they perform on their data sets. I think that that's an important part of the academic review and informatics is to see how these models translate into other health care settings. And we also are interested to make sure that what I said in the prior discussion is correct, that we're only incorporating things that other institutions already have. So I think that that's certainly one. 

The second is a part of a large National Cancer Data standard project called mCODE, the Minimal Common Oncology Data Elements, I chair that executive committee. And one of the pieces of that is trying to find a way to make all of these kinds of structured data interoperable between health records. And so I would just encourage all of my colleagues to always advocate for interoperability and, when there's an option, to store data in a way that makes that data more easily shared in the same formats between institutions. I think that that will pay many dividends for our field going forward. And I just want to plug all the team at mCODE for their work in this and maybe there'll be an integration and connection between mCODE and our project in the future.

 

Dr. Shaalan Beg: Thank you very much Dr. Osterman for sharing your insights with us today on the ASCO Daily News Podcast.

 

Dr. Travis Osterman: Thanks, Shaalan. Have a great day.

 

Dr. Shaalan Beg: And thank you to all our listeners for your time today. You'll find a link to Dr. Osterman’s article in the transcript of this episode. And if you value the insights that you hear on the ASCO Daily News Podcast, please take a moment to rate, review, and subscribe wherever you get your podcast.

 

Disclaimer:

The purpose of this podcast is to educate and to inform. This is not a substitute for professional medical care and is not intended for use in the diagnosis or treatment of individual conditions.

Guests on this podcast express their own opinions, experience, and conclusions. Guest statements on the podcast do not express the opinions of ASCO. The mention of any product, service, organization, activity or therapy should not be construed as an ASCO endorsement.

 

Find out more about today’s speakers:

Dr. Shaalan Beg

@ShaalanBeg

Dr. Travis Osterman

@TravisOsterman

 

Follow ASCO on social media: 

@ASCO on Twitter 

ASCO on Facebook 

ASCO on LinkedIn 

 

Disclosures:

Dr. Shaalan Beg:

Employment: Science 37

Consulting or Advisory Role: Ipsen, Array BioPharma, AstraZeneca/MedImmune, Cancer Commons, Legend Biotech, Foundation Medicine

Research Funding (Inst.): Bristol-Myers Squibb, AstraZeneca/MedImmune, Merck Serono, Five Prime Therapeutics, MedImmune, Genentech, Immunesensor, Tolero Pharmaceuticals

 

Dr. Travis Osterman:

Stock and Other Ownership Interests: Faculty Coaching

Honoraria: Amazon Web Services

Consulting or Advisory Role: eHealth, AstraZeneca, Outcomes Insights, Biodesix, MD Outlook, GenomOncology, Cota Healthcare, Flagship Biosciences, Microsoft, Dedham Group, Oncollege

Research Funding: GE Healthcare, Microsoft, IBM Watson Health

Travel, Accommodations, Expenses: GE Healthcare, Amazon Web Services

Drs. John Sweetenham and Shaji Kumar discuss the emergence of CAR T-cell therapy for multiple myeloma, its benefits and challenges for patients, and its potential role earlier in the treatment of disease.

TRANSCRIPT

Dr. John Sweetenham: Hello, I'm Dr. John Sweetenham from the UT Southwestern Harold C. Simmons Comprehensive Cancer Center and host of the ASCO Daily News Podcast. 

Multiple myeloma is the second most common hematologic malignancy, and the American Cancer Society estimates that there will be more than 35,000 new cases of the disease diagnosed in the United States this year. The emergence of several novel therapies over the last decade has transformed the therapeutic landscape for multiple myeloma, and chimeric antigen receptor – or CAR T-cell therapy – is one of the newest treatments for this disease, which has created a great deal of buzz. 

Dr. Shaji Kumar is an internationally renowned investigator of novel therapeutics and next-generation treatment options for patients with multiple myeloma, and I'm delighted to welcome him to the podcast today to discuss innovations in CAR T-cell therapy in this space. Dr. Kumar is a professor of medicine and chair of the Myeloma Group, as well as chair of research in the Division of Hematology at the Mayo Clinic in Rochester, Minnesota. He is also the editor-in-chief of The Hematologist. 

You'll find our full disclosures available in the transcript of this episode, and disclosures of all guests on the podcast are available at asco.org/DNpod. 

Shaji, it's great to have you on the podcast today.

Dr. Shaji Kumar: Thanks, John.

Dr. John Sweetenham: Shaji, to begin with, maybe we could ask you for an overview of where CAR T-cell therapy sits in multiple myeloma right now. We know that CAR T-cell therapy has improved the survival for some patients with myeloma in recent years. But of course, relapse still remains a problem. Can you tell us a little about the therapies that are currently approved for multiple myeloma in the CAR T-cell space, and what are the potential benefits and challenges of these products?

Dr. Shaji Kumar: Absolutely. It has been a revolution, I think, in terms of therapies for multiple myeloma during the past decade. We have seen so many new treatments approved for myeloma, and consequently, the survival of patients with myeloma has significantly improved. Two decades ago, we used to tell patients a median survival of 3 years, and today we tell patients a median survival of 8 to 10 years, a number that is continuing to go up. And it is all because of the new treatments that have become available for patients, especially over the past decade, and CAR T-cell therapy has been a game changer.  

Now, the main treatments that we were relying on for the past 2 decades have been the immunomodulatory drugs, the proteasome inhibitors, and more recently, the anti-CD38 monoclonal antibodies. Unfortunately, what we see in the clinic is that patients go through these therapies and various combinations of these agents, and often over the 6 to 10 years after the diagnosis, they often become refractory to these drugs. And then we are left with very few choices, if any, for controlling the disease. And that's where the CAR T cells have really made an impact. 

Over the past several years, clinical trials have shown that CAR T-cell therapy is highly effective. In fact, when we look at the initial trials that have been done in this space, the majority of these CAR T cells have been targeted towards what we call BCMA, or a B-cell maturation antigen that is present on both normal and abnormal plasma cells. Now, the concept of CAR T cells has been around for a while, and we have already seen success in other hematological malignancies, but it has been a little late compared to the other diseases in terms of its arrival in the myeloma field. But over the past few years, we have seen some dramatic progress. We currently have two different CAR T cells that are approved and available in the clinic. We have idecabtagene vicleucel (ide-cel) and also ciltacabtagene which is also called cilta-cel. Both of these CAR T cells are targeted towards BCMA.  

In the early trials conducted with both of these CAR T cells, we’ve seen patients who have become refractory to all the available therapies, and now upwards of 90% of these patients are responding to these CAR T cells. We are now seeing responses that we had typically not seen previously in any of the other therapies – not only the high response rates but also the depth of response. What we are seeing is a significant number of these patients – nearly half – of these patients can actually be minimal residual disease (MRD)-negative in the bone marrow after the CAR T-cell therapy. And this is clearly unprecedented in this myeloma space.

Now, the approval for both these CAR T cells has been based on the experience in patients who have become refractory to the currently available therapies. And the ‘line in the sand’ that the FDA has drawn for approval for these drugs has been at least 4 prior therapies. In those patients, when you look at the studies that have been done both for the ide-cel and the cilta-cel, it clearly demonstrates the advantages. And we can look at the data that's available in 3 groups. So we have the single-arm studies, the early phase I and phase 2 trials that have been done with both these CAR T cells. For ide-cel, we have the KarMMa trial, and for the cilta-cel, we have the CARTITUDE trials. In the initial studies, as I previously mentioned, we are seeing responses upwards of 90%, and we are seeing disease control that is lasting at least a year or more with these CAR T cells.  

Now, of course, the question is, we do need randomized phase 3 trials to demonstrate that this is indeed true. Even before the phase 3 trials came along, there have been multiple case-control studies that have been done where the outcomes of patients getting these CAR T cells were compared to real-world controls or cohorts of patients who did not get these therapies. And these studies demonstrated that the outcomes of patients getting CAR T cells were significantly better than what has been shown in the real-world controlled population. And then finally, we have, of course, the phase 3 trials that have read out in patients with relapsed myeloma, in fact, in a group of patients in an earlier stage of the disease than who were studied in those single-arm studies.

Now, based on the results from the single-arm studies, we got the approval from the FDA for the use of CAR T cells in this late stage of the disease. And with the phase 3 trials that have read out, both the KarMMa-3 trial and the CARTITUDE-4 trial again clearly demonstrate that these CAR T cells are much more effective than what we would have seen with the conventional therapies if those patients were assigned to those treatments. Now, clearly, it's not only a question of efficacy. We also know that they do come with some toxicities, and we have a good sense of the toxicities from those initial phase I and phase 2 trials. Now, as we have seen with the other diseases, the 2 major categories of toxicities that we see are the cytokine release syndrome and the neurological toxicity associated with CAR T-cell therapy. 

In terms of the clinical features and the presentations, they are not different than what we have seen with the CAR T cells used in other hematological malignancies, but we do see different frequencies of these in the myeloma patient population. The cytokine release syndrome is something that is seen in a majority of the patients, at least in the lower grades. And over the time since we have been using CAR T-cell therapy, I think we have all become a lot more familiar with the management of the cytokine release syndrome, and we have very effective therapies to manage, and to some extent, maybe even prevent the onset of the cytokine release syndrome in patients undergoing CAR T-cell therapy. 

The neurological toxicity is another toxicity that is unique to these immunological therapies, known as the ICANS, or the immune cell effector-associated neurological syndromes. And these, again, thankfully, are much less frequent than what we see with the cytokine release syndrome. But even with the ICANS and other neurological toxicities associated with CAR T-cell therapy, we have a better understanding of the biology behind it, and we also have better modalities to monitor the patients for these toxicities and intervene in an appropriate and timely manner to take care of them. 

In addition to the ICANS and the cytokine release syndrome, we certainly do see other toxicities as well. We do see hematological toxicities, which are common for many of the treatments we use for hematological malignancies. Thankfully, these other toxicities can be easily managed. They often reverse themselves over time and haven't really posed any major hurdles in terms of the utilization of these modalities of therapy for patients with myeloma.

Dr. John Sweetenham: Okay, that's great. Thank you very much, Shaji. I'll return to some of the potential late effects of CAR T-cell therapy in a moment. But before we get to that, as you know, in other hematologic malignancies, there has been a trend in recent years to moving CAR T-cell therapy further up the therapeutic algorithm, as it were. So there is consideration being given to using this as a first-line or second-line therapy. Do you think there is a potential role for CAR T cell earlier in the treatment of multiple myeloma? For example, could you see a time when it may be used as second-line treatment for this disease?

Dr. Shaji Kumar: Absolutely. I think that's a very good point. And I think, just as with other cancers and as with myeloma, too, with many of the therapies we use for myeloma in the newly diagnosed setting or the time of first relapse, were all initially tested in these later relapses. We are following the same script even for the CAR T cells. In fact, the 2 phase 3 trials, the KarMMa-3 trial and the CARTITUDE-4 trial, enrolled patients in the earlier lines of therapy, either 1 prior line or 2 prior lines for these trials. And what we have seen with both phase 3 trials is that the outcomes, both the progression-free survival outcomes and the response rates, are significantly better compared to the standard-of-care therapies that these patients would have otherwise received. 

Now, what is unclear at this point is, does every patient at the time of the first relapse need a CAR T-cell therapy, or can we be more selective in terms of deciding which particular subgroup of patients can benefit more from this CAR T-cell therapy in different lines or different relapses? The bottom line is, I think the data that we have right now clearly points towards the utility of CAR T-cell therapy at earlier lines of treatment. The question now is, which patients do we need to do at which stage? In fact, when you look at the newly diagnosed setting, there are ongoing clinical trials that are looking at replacing autologous stem cell transplant with CAR T-cell therapy. Those phase 3 trials are currently enrolling where patients are being randomized to either the autologous stem cell transplant, which is considered a standard of care for eligible patients, or giving them a CAR T-cell therapy. Similarly, even in transplant-ineligible patients, trials are exploring the possibility of using CAR T-cell therapy instead of giving patients a prolonged course of maintenance and consolidation. 

One of the beauties with the CAR T-cell therapy right now is that it's a one-time treatment. You get the treatment and you do not get any additional therapies after that. It’s a protocol that is being debated –

whether we will need maintenance therapies after CAR T-cell therapy, but I think that is something that will have to be explored in the context of clinical trials. But certainly, I think over the next 5 years, we will see the CAR T-cell therapy moving to earlier and earlier lines of therapy. My guess is in 5 years, there will be a subset of patients where we would offer them CAR T-cell as part of the first-line therapy, some others, maybe based on disease and patient characteristics, we might use it at the time of first or second relapse.  

Dr. John Sweetenham: Great, thank you. Just to return to toxicities and some of the potential late effects. As you know, last November, the FDA launched an investigation to determine whether CAR T-cell therapy can, in rare cases, cause secondary cancers. You may remember that this was in response to reports of T-cell malignancies in patients who had received various types of CAR T-cell immunotherapies. The FDA determined that the risk of T-cell malignancies is applicable to all of the currently approved BCMA-directed and CD19-directed genetically modified autologous CAR T-cell immunotherapies. Could you care to comment on this whether you have seen any evidence of this in your own work, and whether the events and the FDA investigation have impacted your clinical research or your clinical practice in any way in terms of patient monitoring or maybe in terms of trial approval?

Dr. Shaji Kumar: This has been an important observation. As with all new therapies, whenever the question of long-term toxicities is brought up, especially second malignancies, it is something that needs to be looked into very carefully, and I think the FDA is doing exactly that. There have been reports of second cancers, particularly T-cell cancers. In fact, there were some statements that came out recently from the FDA where they commented on the fact that they had seen 22 cases of T-cell cancers by the end of 2023. And, in fact, in 3 of those cases where genetic sequencing was performed, they did notice that the genetic material or the chimeric antigen receptor was inserted into these cancer cells as part of the process. So I think there is a lot more work that needs to be done in terms of understanding the mechanism and probably also understanding how prevalent these instances are. 

But I think, based on what we know as of now, these cases form a very tiny fraction of the total number of CAR T-cell therapies that have been used in patients with lymphoma and myeloma. In our own day-to-day practice, this has not really affected how we view this therapy. It clearly has made a significant impact for patients with no other treatment options. So in our daily practice, we continue to use CAR T-cell therapy as we have done before these reports came out. But we do inform patients about the risk and what we know about the risk of these T-cell malignancies.  

In addition to T-cell malignancies, there have also been reports of myelodysplastic syndromes in patients undergoing CAR T-cell therapy. Again, it is important to remember that, at least in the myeloma setting, many of these patients have had multiple lines of therapy, often with drugs that can cause second malignancies, particularly myelodysplastic syndrome. So I think a lot more work needs to be done in terms of understanding what is the direct impact of CAR T-cell therapy versus what was lurking underneath because of the treatments that these patients had previously received. So I think it is important for us to continue to be very diligent, as with any new therapies that we introduce for the treatment of our patients. But at the same time, understand that, in the context of the benefits that these therapies bring to our patients, especially when they have no other treatment options. 

Dr. John Sweetenham: Absolutely. So, at least for now, and probably in the longer term, the benefits of the therapy certainly appear to outweigh the risks, although it is important not to underestimate or minimize those risks.  

I wanted to change direction a little bit and talk a little bit in the final question about care disparities and CAR T cell. Of course, CAR T-cell therapy is typically offered at large cancer centers and is very expensive. This means that there are issues of access to treatment. In addition, the literature shows us that non-Hispanic Black individuals are twice as likely to develop multiple myeloma compared to their White counterparts. Furthermore, at least right now, Black patients are less likely to receive these novel CAR T-cell therapies and continue to be underrepresented in clinical trials. So, this is a big, complex question, but can you talk a little bit about how outcomes differ between racial and ethnic groups who actually receive CAR T-cell therapy for multiple myeloma? And could you address what you think are the most appropriate strategies for minimizing the disparities in access?

Dr. Shaji Kumar: That's a very, very important question, particularly in the context of multiple myeloma, where African American individuals are at a higher risk of getting plasma cell malignancies. I think we need to think about this in the context of what we know about disparities even before the CAR T cell came along. There has been a good amount of literature that has looked at the outcomes based on the types of therapies that could be impacted by this. There have been studies that have looked at cooperative group trials, which often have a good representation of minorities and have shown that if patients have equal access to advanced therapies that we have, their outcomes are comparable or sometimes even better for African American patients compared to Caucasian patients. So I think it’s very important that the treatment strategies that we develop are equally accessible to everyone. 

In terms of CAR T-cell therapy or immunotherapies, I don’t think we have any concrete evidence to suggest that there is any difference in outcomes. And I think it's reasonable to assume that if patients are exposed to similar therapies, they will have similar outcomes, even in the context of immunotherapies. But at the same time, I think we must continue to study this diligently, and the only way to do that is to ensure that clinical trials include patients reflective of society in general. This will allow us to understand if any differences exist. In addition, I think there is a serious risk that with these expensive therapies, this gap can only widen. And I think that is one reason that we must be proactive, particularly with therapies like CAR T-cell therapy, which not only are expensive but also require quite a bit of logistical support for patients to go to larger centers to get these therapies, stay around these larger centers for upwards of a couple of months, which means they are living outside of their usual societal structure, and ensure there is access to the resources that are needed to enable them to do that. So I think there is a lot that is still unknown, but I think we really need to be proactive in ensuring equal access to these therapies.

Dr. John Sweetenham: Yes. Thanks for a very thoughtful response to that question, also for the work that you are obviously doing to help address this extremely important issue. 

I’d like to thank you for sharing your insights with us today and for the extraordinary work that you’re doing and your team are doing to advance care for patients with multiple myeloma.

Dr. Shaji Kumar: Thank you, John.

Dr. John Sweetenham: And thank you also to our listeners for joining us today. If you value the insights you hear on the ASCO Daily News Podcast, please take a moment to rate, review, and subscribe wherever you get your podcasts. 

Disclaimer: 

The purpose of this podcast is to educate and inform. It is not a substitute for professional medical care and is not intended for use in the diagnosis or treatment of individual conditions. The guests on this podcast express their own opinions, experience, and conclusions. Guest statements do not necessarily reflect the opinions of ASCO. Mention of any product, service, organization, activity, or therapy should not be construed as an ASCO endorsement.

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Dr. Shaji Kumar

@myelomaMD

 

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Dr. John Sweetenham:  

Consulting or Advisory Role: EMA Wellness  

 

Dr. Shaji Kumar:

Consulting or Advisory Role: Takeda, Janssen Oncology, Genentech/Roche, Abbvie, Bristol-Myers Squibb/Celgene, Pfizer, Regeneron, Sanofi, K36

Research Funding (Inst.): Takeda, Abbvie, Novartis, Sanofi, Janssen Oncology, MedImmune, Roche/Genentech, Carsgen Therapeutics Ltd., Allogene Therapeutics, GlaxoSmithKline, Regeneron, Bristol-Myers Squibb/Celgene

Travel, Accommodations, Expenses: Abbvie, Pfizer

Drs. Hope Rugo and Sara Tolaney discuss the promise of antibody-drug conjugates (ADCs) in the treatment of breast cancer, highlighting key trials that shed light on matching the right ADC to the right patient in the right setting. They also explore how combinations and sequencing of ADCs can augment their efficacy, the mechanisms of resistance, and the future potential of biomarkers to predict patient response.

TRANSCRIPT

Dr. Hope Rugo: Hello, I'm Dr. Hope Rugo, your guest host of the ASCO Daily News Podcast today. I'm a professor of medicine and director of breast oncology and clinical trials education at the University of California, San Francisco's Comprehensive Cancer Center.

Antibody-drug conjugates, or ADCs, are rapidly changing the treatment landscape for patients with breast cancer. ADCs consist of antibodies that target tumor-specific antigens on the cell surface, chemical linkers, and cytotoxic payloads that can act powerfully to kill cancer cells. On today's episode, we'll be discussing advances in research to match the right ADC to the right patients and in the right setting. We'll also talk about the next steps, assessing how combinations and sequencing of ADCs can augment their efficacy, improve options for patients, and identify biomarkers in the future to predict how patients will respond so that we can match the right treatment to the right patient and their tumor. We need to gain a better understanding of the mechanisms of resistance that occur upfront as well as under the pressure of treatment. 

Joining me for this important discussion is Dr. Sara Tolaney. Dr. Tolaney is an associate professor of medicine at Harvard Medical School, associate director of the Susan Smith Center for Women's Cancer, and chief of the Division of Breast Oncology at the Dana-Farber Cancer Institute in Boston. 

You'll find our full disclosures in the transcript of this episode and disclosures of all guests on the podcast are available at asco.org/DNpod.

Dr. Tolaney, we're delighted to have you on the podcast today. Thanks for being here.

Dr. Sara Tolaney: Thank you so much for having me. I'm looking forward to the discussion.

Dr. Hope Rugo: Great! So, we'll move forward, and because we're friends and colleagues, I'm going to refer to you as Sara, and I'm Hope, since we’ll dispense with formalities in our discussion. 

A lot of the talks that we give about ADCs start out with “a revolution in breast cancer therapy.” And indeed, this is a really exciting time with ADCs as treatment for breast cancer, and we're rapidly moving these agents into earlier disease settings. Can you tell us a little bit about the possibilities and challenges of using ADCs for the treatment of breast cancer today?

Dr. Sara Tolaney: It's interesting that you say antibody-drug conjugates as revolutionizing outcomes of breast cancer, which I think is true. But on the flip side, I think it's also bringing up a lot of questions about how to use them, when to use them, and how to manage side effects. So there are a lot of good strengths for these antibody-drug conjugates, but a lot of unknowns that we're still trying to figure out. We had an older antibody-drug conjugate T-DM1 that we were all very familiar with that for years had been a treatment that we used very commonly in metastatic disease and now even use in early breast cancer, and I think has changed outcomes for patients. But over time, we've been able to develop newer antibody-drug conjugates as the technology has really evolved so that these agents now are able to deliver a lot of chemotherapy into a cancer cell. We're seeing very high drug-to-antibody ratios, and we're also seeing that these drugs can function via bystander effect, whereas T-DM1, for example, was not able to do that. But our newer ADCs, like sacituzumab govitecan or trastuzumab deruxtecan, are agents that do allow chemotherapy to get into that cancer cell, but also to get into neighboring cells. 

And I think the technology evolution in being able to build these so-called next-generation ADCs has allowed for really unprecedented efficacy that we've not seen before. And it's also allowed us to develop these drugs in a way that's been different. Originally, we were developing T-DM1 to turn off HER2 signaling and to deliver chemotherapy into a HER2 cell. At least that's what we thought originally. And now we're really evolving so that we can just find a tiny bit of protein on a cancer cell and use it as a target, really in a subtype-agnostic way. And I think it's just a different way of thinking about how to use these agents to really deliver a lot of chemotherapy into cancer cells and have very robust efficacy.

Dr. Hope Rugo: Yes, it is fascinating that some of the suppositions that we made with the first ADC don't seem to really hold true as well. And maybe they hold true in varying levels for the different ADCs. For example, this bystander effect is thought to allow us to target cells that have very low expression of the receptor that can be internalized even lower than our ability to detect these receptors by immunohistochemistry. And maybe we'll talk about that in a little bit.  

But first, you mentioned already sacituzumab and trastuzumab deruxtecan, the ADCs that are currently approved for breast cancer. But can you tell us a little more about those ADCs and the key trials that have led to approval of these targeted agents?

Dr. Sara Tolaney: Yes, I think when we first saw the data that came out with T-DXd and DESTINY-Breast01, I think my jaw dropped because I had never seen a waterfall plot like that. This was a single-arm study that looked at T-DXd in patients with very heavily pretreated metastatic HER2-positive breast cancer and saw very high response rates of over 60% and a clinical benefit rate of almost 98%, meaning that almost every single patient who got the drug and had a median of six prior lines of therapy had reduction in tumor size. And that’s unreal. I think it was revolutionary in the sense that we had never seen that kind of activity in such a pretreated population.

The agent was studied in other registration trials, DESTINY-Breast03, which looked at T-DXd and compared it head to head with T-DM1 in a predominantly second-line metastatic HER2-positive population, and here, again, unprecedented results. I’ve never seen a p value like that or a hazard ratio of, again unreal, of a little under 0.3 and seeing a 28-month PFS with T-DXd relative to just a little under 7 months PFS with T-DM1. We have never seen patients with metastatic HER2-positive breast cancer have a PFS that long. Even in CLEOPATRA, it’s a little under 19 months in the first-line setting, where people were predominantly naïve to HER2-directed therapies. This, again, is really changing outcomes for patients.  

But then, I think, when we go to the next step, we studied T-DXd in patients with HER2-positive breast cancer and it had again these unprecedented results. But there was some early data suggesting that it could even work in tumors that weren't truly HER2-positive but what we call HER2-low, meaning that they weren’t HER2/3+, they weren’t HER2-0 but they were 1+ to 2+ and not FISH amplified. And so even with a little bit of protein there, they were seeing activity in the early phase studies and so it led to DESTINY-Breast04, which compared T-DXd to chemotherapy of physician's choice in people who had had one or two prior lines of chemotherapy in the metastatic setting. It was predominantly geared to look at outcomes in hormone receptor-positive breast cancer. But there was a small group of 58 patients with triple-negative disease that were also included in that trial. And here again, a very unprecedented outcome seeing a response rate of about 50%, which, again, we never see in pretreated hormone receptor-positive disease. And a PFS of 10 months, and again, these are people who already had one or two prior lines of chemotherapy. So it’s, again, really changing outcomes. And so now I think it leads us to a lot of other questions that we are addressing in trials - can this drug work even if the tumor has maybe no HER2 expression, what about HER2-0, what about HER2-ultra low, meaning a little bit of staining but not quite 1+. And so these are questions that I think we will need to address and there are studies that will help us address that.

On the flip side, we saw sacituzumab govitecan get developed in breast cancer. Initially, we saw very impressive results from a single arm study of sacituzumab in metastatic triple-negative disease where we saw response rates of a little over 30%. These are patients who were very heavily pretreated with metastatic triple negative breast cancer where, unfortunately, response rates end up being in a 5% range so it was a home run in that setting. So that led to the ASCENT trial, which compared sacituzumab govitecan to treatment of physician's choice therapy and that study really enrolled people who were, in essence, second line and beyond in the metastatic triple-negative setting and showed almost triple progression free survival, in essence, doubled overall survival. So again, very robust efficacy leading to confirming its approval. And then we saw data from TROPiCS-02, which looked at sacituzumab in metastatic hormone receptor-positive disease and also showed improvements in both progression free and overall survival. And this was in pre-treated populations of 2 to 4 prior lines of chemotherapy. These agents, again, have established robust efficacy, and so now the idea is can we move these drugs earlier in development into earlier line settings and can we even move these agents into the early disease setting and potentially cure more patients? So hopefully, we’ll figure out ways to make that happen.

Dr. Hope Rugo: Yeah, that was a great summary of this exciting data. And I think we really got an idea of what waterfall plots could tell us from DESTINY-Breast01 where you could count the number of patients whose cancers grew with therapy on one hand. It's been a huge advance. I think it’s where we get this “revolution” even in patients with a median of 4 lines of prior chemo, and, in the ASCENT trial, we were able to see this improvement and survival in the hardest-treated subset of metastatic breast cancer triple negative disease. And then the remarkable data in HER2-positive and HER2-low breast cancer hormone receptor positive disease. We’re really covering all of the subset of breast cancers.  

When we introduce new therapies though, and of course, our interest is moving them earlier as lines of therapy in the metastatic setting, we really have to think about the adverse events and how those are going to affect their patients, and balancing the risk benefit ratio. Obviously when the benefit is so huge, we’re more thinking about how do we proactively manage these side effects, educate our patients, use prophylaxis when possible. Can you share with us some of your insights on management strategies for toxicities? 

Dr. Sara Tolaney: You bring up a very good point, and I will say the ADCs were designed with the idea being that we could deliver a ton of chemotherapy into a cancer cell. So obviously, my hope had been that we weren't going to see a lot of chemotherapy-like side effects because the goal was to try to spare normal cells of these side effects. But unfortunately, we do see that these agents do have real toxicities, and I think that is an important message. So, for example, with sacituzumab, for people who have hair going into it, they will lose their hair during the course of treatment, and so that's important to make patients aware of. It can lower blood counts, and about 50% of patients who are on sacituzumab will end up needing growth factor support while they're on treatment. So, that is again something that needs to be monitored and managed. But usually, we're pretty good at managing neutropenia, and with the growth factor support, I find that it actually works really well. 

Another thing with sacituzumab is the potential risk of diarrhea, but most of the diarrhea is low-grade diarrhea. It’s rare that you get someone who has high-grade diarrhea with sacituzumab. Usually, I find it works to just instruct patients to use loperamide as needed. And again, usually that works well. And certainly when needed, dose modification can also help with these side effects and so it is important to keep in mind that this is another option. With T-DXd, one thing that we do have to keep in mind as an unusual side effect is the potential risk of interstitial lung disease. We see that in about 10% to 15% of patients getting T-DXd. That is something that we do have to be very mindful of. For the most part it is low-grade ILD. But there are rare occasions where there have been deaths from ILD. And we're seeing with some of the newer trials, the death rate is usually under 1%, but it is a real potential risk. And so it is really important to counsel patients when getting T-DXd about this potential side effect, that way they are good about communicating with you if they get any new symptoms, such as shortness of breath or dry cough, to get you aware of it and can work it up and get imaging certainly if that occurs. 

And then I think the management for ILD is a little unique and a little different truthfully than the way we manage pneumonitis from other drugs. Normally, when I am treating patients who develop pneumonitis, even if it is mildly symptomatic, we often will hold treatment, give steroids, and rechallenge them when it gets better. But with T-DXd, if anyone develops symptomatic pneumonitis, you actually have to permanently discontinue the T-DXd per the guidelines because we just don't know the safety of being able to rechallenge that patient once that pneumonitis resolves. For grade 1 ILD, meaning someone who has, for example, ground glass changes seen on imaging but doesn't have any symptoms, you have to hold the drug and wait until those imaging findings resolve and then you can restart. I usually do treat grade 1 ILD patients with steroids with the hope being that maybe it will allow for the pneumonitis to resolve more quickly, although in truth I don't know if that's the case. I have just taken that approach because I don't like leaving patients off the drug for too long if not needed. Again, I typically treat them with steroids, reimage in three to four weeks, and see if I’m able to restart. If they resolve within 28 days, you can restart at the same dose. If it takes longer to resolve, you need to dose modify. 

And then I think the other big thing with T-DXd is to know that it is categorized as a highly emetogenic agent. Most of us are using three-drug prophylaxis, which I think works really well. It is also important to realize that there can be some delayed nausea, which is a little unusual with some of our other agents. And so to warn patients about that and I find that use of olanzapine or ondansetron for the delayed nausea tends to work pretty well. 

Hope, do you have any pearls for us? Obviously, you are very experienced in using these agents; are there any things you would recommend for the management of ADCs? 

Dr. Hope Rugo: Yes, it's such a great question and an important area because, particularly as we are using these agents earlier, we really need to have strategies for both how long to continue as well as manage the toxicities. I agree with the nausea, olanzapine has been really a great addition, and using a triplet as initial premedication makes a big difference for T-DXd and other deruxtecan ADCs that are in the pipeline. And then I think that the ILD issue, we’re really learning more about the risk factors as well as retreatment. And hopefully, we’ll have more data this year at ESMO Breast and maybe ASCO on retreatment for grade 1. We certainly now do not have any data on the safety of retreatment for grade 2, so that is really not accepted now. For sacituzumab, I think the interesting area is the metabolism and the impact. So with neutropenia, as we move the drug earlier, it's easier and easier to manage, we see less severe neutropenia. We can give growth factors, which we are all good at in oncology. But I think the question about managing diarrhea and who is at risk still exists. Understanding pharmacogenomics and UGT1A1 is an interesting area where patients who have diarrhea could be tested to see if they are poor metabolizers which affects a little under 10% of the overall population. Because in that group, you could give less drug and get the same benefit with less toxicity. So I think this is all very interesting. It is important for providers and patients to be educated so that we can manage this appropriately. And I think you gave an excellent overview.  

We have new agents in the pipeline also and maybe we’ll talk about those next, and then we’ll talk a little bit about sequencing and resistance, as well as the unmet need for brain metastases. So lots of areas to talk about. There are a number of TROP-2 ADCs that are in the pipeline, and one that has presented phase III data, datopotamab deruxtecan. But other studies are being developed with new TROP-2 ADCs as well. But then there are a huge number of ADCs there with new targets, for example, immune effector targets, and new payloads, even immunotherapy and two different payloads or bispecific antibodies. And then there is interest in combining ADCs with immunotherapy and PARP inhibitors. We saw data in bladder cancer, I think it was bladder cancer, with combined 2 different ADCs at ESMO in 2023. So a lot of new approaches. How are we going to manage this moving forward? And where do you think we are going to position some of these next sort of "me-too" drugs? 

Dr. Sara Tolaney: It's an excellent question, and you're right, the field is exploding with new antibody- drug conjugates. So, it's going to leave us with this conundrum of what to do. And you brought up the really interesting example of the fact that we have an approved TROP-2 ADC, we have as sacituzumab govitecan, and for example, we've recently seen some really exciting data come out from TROPION-Breast01 looking at another TROP-2 ADC, datopotamab deruxtecan or Dato-DXd where that ADC performed better than chemotherapy in a head-to-head trial in terms of progression-free survival in a hormone receptor-positive population. Then there's another TROP-2 ADC, moving forward in development moving to phase III that Merck is developing MK-2870. All three of these ADCs are targeting TROP-2 and have a TOPO 1 payload. So, it leaves you with the question of how do you think about that? Is there going to be a role for using serial TROP-2 ADCs? Could one work after the other, even when they have very similar payloads? How are we going to incorporate them? How do you pick one over the other? So, it is going to be tricky for us as we get more and more of these agents. I think we're all excited about seeing ADCs that may have different targets and different payloads, where maybe we will see that sequential utilization will have robust efficacy if we swap things out. Again, we don't have data here yet, but I think there are other agents in development. For example, you could think of like, disitamab vedotin targets HER2 and has an MMAE payload. So, could it be that someone progresses on T-DXd for HER2-low, but then could go on to disitamab vedotin? How will that work? So, we have a lot to learn, but it's really nice to have so many options. 

Dr. Hope Rugo: Yeah, it'll be interesting to see whether or not we select the ADC based on a rational understanding of the tumor and the patient, or whether it's simply what's easier to give and has the right toxicity for that patient. 

So, that sort of brings us to our next topic, which is how are we going to sequence these agents? How are we going to understand the mechanisms of ADC resistance? At San Antonio in 2023, we saw a presentation where there was a top-alteration, and the patient had a really long response to a top-directed ADC, or an agent that carried a topoisomerase inhibitor. And that really struck me that we're going to see these alterations. There was a fresh autopsy study that suggested that the alterations may be different in different organ sites of disease. How are we going to figure this out?

Dr. Sara Tolaney: Yeah, I also was really puzzled to see those data from San Antonio where we've sort of simplified ADC resistance in our heads to say, well, maybe someone becomes resistant because they lose target expression, or maybe someone becomes resistant because they've developed resistance to the payload, kind of like the way we think of someone developing resistance to getting chemotherapy. But obviously, it's probably far more complex than that. With these ADCs, they need to be able to internalize the ADC and could there be mechanisms of resistance related to the internalization process? So, I think there are lots of potential areas where resistance could be occurring. I think, we don't understand it very well. We've seen patients, for example, who have responded. This is just anecdotal, but we have data, for example looking at, Dato-DXd in the phase 1 triple-negative study where there were some patients who responded despite having progressed on sacituzumab. Well, why is that? You would think if it's target resistance or payload resistance, it would be the same target and a very similar payload. So, why would those drugs work one after the other? And that's why I think we just don't understand this well enough at this point in time.  

So, it's clearly an area where more research is needed because it does have significant implications on how we think about using these drugs sequentially. We will need to understand these resistance mechanisms because there do seem to be some rare patients who benefit from these sequencing strategies and then others who don't. So, it would be nice to be able to figure this out and hopefully in the future, we'll be able to test patients and know what drugs to give them. But I think we're far off from that, unfortunately, right now.

Dr. Hope Rugo: Yeah, it does seem to be a relatively elusive approach, and I think, in part, it's due to the heterogeneity of cancer. And maybe, as we're better and better at analyzing tumor cells in the blood, which are a rare group, and ctDNA, which, of course, we do now to look for mutations, maybe that'll be an approach that we'll be able to take. And also, of course, moving the drugs earlier into the disease setting with less heterogeneity and mechanisms of resistance might help as well. 

I was fascinated by the fact that although the PFS to the first ADC seems to be overall much greater than the PFS to the second ADC, when you sequence them, there are a few patients who have a longer PFS with the second, even if these are just sacituzumab T-DXd sequencing in various directions. So, it's clearly very complex. And right now, I think we're just sequencing and we don't really know how to do it. We just choose what we think is best for that patient first and go on to the next one later, which is interesting. And one of the choices might be treating brain metastases, which of course remains a huge unmet need. And if we could find effective treatment for brain metastases, maybe we could also prevent them in some patients more. What do we know about the central nervous system (CNS) penetration of ADCs and the clinical results?

Dr. Sara Tolaney: At first, we were not optimistic that these drugs would have activity in the brain because we thought that these were very large agents that probably couldn't penetrate into the blood-brain barrier. But in fact, I think we were all very excited to see that there is actually data suggesting that these drugs can actually have robust efficacy in the CNS in patients who have active brain metastases. And so what we've seen so far is data with trastuzumab deruxtecan or T-DXd, there have been some trials that have been done, including studies like DEBRA and TUXEDO, which have looked at T-DXd in patients who have active brain metastases and are showing very robust response rates within the CNS. So, we're seeing intracranial response rates on the order of 40% to 50%. And clinically, this is what we're seeing as well. These are smaller studies and there's a larger trial, DESTINY-Breast12, which will hopefully validate the robust efficacy in the CNS with T-DXd. So, again, it's really nice to see this. 

To your point, though, one area that I'm curious about, as you were alluding to, is will these drugs be able to prevent CNS disease? And I think that is a very different question because here the blood-brain barrier is not intact when patients have progressive brain metastases, and so these ADCs are causing robust activity. But if you look, for example, and I'll be curious to see what happens, DESTINY-Breast05 is looking at T-DXd in the post preoperative setting for patients who have residual disease and comparing it to T-DM1. And unfortunately, we saw that T-DM1 was not able to prevent brain metastases when looking at data from KATHERINE, where in fact, rates of CNS as the first site of recurrence were similar with T-DM1 and trastuzumab. So, now we'll be interested to see, will it be any different with T-DXd? Will T-DXd be able to have any role in prevention? I think we haven't seen anything like that with ADCs to date, so that would be a paradigm shift in our way of thinking. 

Right now, there are strategies being taken from a prevention standpoint of trying to add a tyrosine kinase inhibitor in that early-stage setting, such as what is being done in the COMPASS-RD trying to add tucatinib to T-DM1 to see if that would do it. But again, we really need to understand, again, how these drugs work, particularly when the blood-brain barrier may not be intact. But again, very exciting data with T-DXd in an ongoing trial, actually through SWOG looking at sacituzumab for patients with CNS disease. And we've seen some preliminary data with sacituzumab showing that it actually does penetrate into the brain when they've looked at drug levels in the tumor in the brain, comparing it to plasma, it actually looks similar. So, we know it's getting in there and we'll have more robust efficacy data, hopefully coming soon.

Dr. Hope Rugo: Yeah, that was a great summary of that data. It's been exciting also to see some responses in patients with leptomeningeal disease as well, where we've really been struggling with anything that works for more than a few weeks or months at the most. So I'm holding out great hope that we're going to see a big difference because even though TDM-1 had some efficacy, it was nothing like what we're seeing with T-DXd. So we'll see. And the same with sacituzumab with triple negative disease, where sometimes brain metastases can be an isolated site of recurrence, even in patients who have a pathologic complete response. So it has been a big challenge. 

So I think that what we've learned from you is a lot about the mechanisms and the data about these new ADCs, the tremendous hope that these are bringing to our patients, but also the really exciting new approaches with new payloads, new targets of drugs that are in development, as well as potentially some different ADCs that have the same target and similar mechanisms of action of this payload. Really fascinating to hear about this, the future work on sequencing, on mechanisms of resistance, and on brain metastases. We have, of course, 2 prospective trials that we'll be looking at sequencing, one with T-DXd and Dato-DXd, and one registry trial with T-DXd and sacituzumab govitecan in the US. So that's also going to, I think, provide us with some important information. 

We could talk for a long time about this, but I just wonder if you have any closing comments to sum up your thoughts. 

Dr. Sara Tolaney: I think you did a great job leading us through thinking about ADCs, and I think it'll be really interesting to see what happens in the future. While again, these agents have become a standard for us for patients with metastatic disease, I'm going to be curious to see how everything evolves and to see if we'll be able to substitute chemotherapy with ADCs in early disease settings and change outcomes. Will we be able to have novel combinations? Will we be able to sequence these drugs one after another? Will we actually have biomarker predictors to help us sort out which drug to give when? So, still a lot to learn, but clearly a very exciting field right now.

Dr. Hope Rugo: Indeed. Sara, thank you for sharing your valuable insights with us today on the ASCO Daily News Podcast on your great work to develop novel therapies for breast cancer. It's always a pleasure to talk to you, and even greater to work with you on the future progress of treatment for breast cancer.

Dr. Sara Tolaney: Thank you so much, Hope. Again, really nice to always discuss these data with you. I always learn a lot, so thank you.

Dr. Hope Rugo: Thank you. And thank you to our listeners for joining us today. You'll find a link to all of the studies discussed today in the transcript of this episode. Finally, if you value the insights that you hear on the ASCO Daily News Podcast, please take a moment to rate, review, and subscribe wherever you get your podcasts.

Disclaimer:

The purpose of this podcast is to educate and inform. This is not a substitute for professional medical care and is not intended for use in the diagnosis or treatment of individual conditions. Guests on this podcast express their own opinions, experiences, and conclusions. Guest statements on the podcast do not express the opinions of ASCO. The mention of a product, service, organization, activity, or therapy should not be construed as an ASCO endorsement.

 

Follow today’s speakers:  

Dr. Hope Rugo 

@hoperugo 

Dr. Sara Tolaney

@stolaney1

 

 

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Disclosures:  

Dr. Hope Rugo: 

Consulting or Advisory Role: Napo Pharmaceuticals, Puma Biotechnology, Mylan, Eisai, Daiichi Sankyo

Research Funding (Inst.): OBI Pharma, Pfizer, Novartis, Lilly, Genentech, Merck, Daiichi Sankyo, Sermonix Pharmaceuticals, AstraZeneca, Gilead Sciences, Astellas Pharma, Talho Oncology, Veru, GlaxoSmithKline, Hoffmann-LaRoche AG/Genentech, Inc, Stemline Therapeutics

Travel, Accommodations, Expenses: Merck, AstraZeneca

 

Dr. Sara Tolaney:

Consulting or Advisory Role: Novartis, Pfizer, Merck, AstraZeneca, Genentech, Eisai, Sanofi, Bristol-Myers Squibb, Seattle Genetics, CytomX Therapeutics, Daiichi Sankyo, Immunomedics/Gilead, BeyondSpring Pharmaceuticals, OncXerna Therapeutics, Zymeworks, Zentalis, Blueprint Medicines, Reveal Genomics, ARC Therapeutics, Umoja Biopharma, Menarini/Stemline, Aadi Bio, Artio Biopharmaceuticals, Incyte Corp, Zetagen, Bayer, Infinity Therapeutics, Jazz Pharmaceuticals, Natera, Tango Therapeutics, Systimmune, eFFECTOR Therapeutics, Hengrui Pharmaceutical (USA), Sumitovant Biopharma

Research Funding (Inst.): Genentech/Roche, Merck, Exelixis, Pfizer, Lilly, Novartis, Bristol-Myers Squibb, Eisai, AstraZeneca, NanoString Technologies, Seattle Genetics, OncoPep, Gilead

Travel, Accommodations, Expenses: Eli Lilly, Sanofi, Gilead Sciences

Drs. Shaalan Beg and Rachna Shroff discuss key abstracts on GI cancers that were featured at the 2024 ASCO Gastrointestinal Cancers Symposium, including SKYSCRAPER-08, EMERALD-1, and NEST-1 in esophageal squamous cell carcinoma, hepatocellular carcinoma, and colorectal cancer, respectively.

TRANSCRIPT

Dr. Shaalan Beg: Hello, and welcome to the ASCO Daily News Podcast. I'm Dr. Shaalan Beg, your guest host of the podcast today. I’m an adjunct associate professor at UT Southwestern's Simmons Comprehensive Cancer Center and vice president of oncology at Science 37. Today, we'll be discussing key abstracts and other exciting highlights from the 2024 ASCO Gastrointestinal Cancers Symposium. Joining me to discuss some key takeaways from the meeting is the chair of this year's Symposium, Dr. Rachna Shroff. Dr. Shroff is the division chief of Hematology Oncology and chief of GI Medical Oncology at the University of Arizona Cancer Center. She also serves as the associate dean for clinical and translational research at the University of Arizona College of Medicine – Tucson.

Our full disclosures are available in the transcript of this episode, and disclosures related to all episodes of the podcast are available at asco.org/DNpod. 

Dr. Shroff, welcome back to the ASCO Daily News Podcast, and congratulations on a great Symposium. The scientific advances and innovative, multidisciplinary approaches that were featured throughout the meeting were really inspiring and reflect the incredible strides we’re making in GI cancer research.

Dr. Rachna Shroff: Thank you so much for having me back. I am delighted to be here. 

Dr. Shaalan Beg: Dr. Shroff, the theme of this year's symposium was "Taking Personalized Care to the Next Level." I’d love to hear your reflections on the sessions that you found most exciting and really resonated with the attendees. 

Dr. Rachna Shroff: Yes, thank you. We were really excited about this theme because we really felt that “Taking Personalized Care to the Next Level” translated to thinking through personalized approaches to patient care, not just in the traditional ways that we think of with precision oncology and genomics driving our care, but also how we can think through multidisciplinary approaches and an individualized care plan. Thinking through how artificial intelligence and novel clinical trial designs can and should be implemented to meet the needs of our individual patients. And so we really highlighted that in what was a somewhat new reboot of a session called “Intersections,” which were every day and were really more cross-tumor; they were tumor agnostic but were thematic focused. As I mentioned, those themes were really based on feedback that we had from prior attendees, as well as from the program committee’s feeling on what are really the questions that we are dealing with and that are burning in the clinic today and that includes the emerging role of artificial intelligence and machine learning and how we integrate that into our clinical care, approaches to oligometastatic disease, and it’s not really just something that we think of in colorectal cancer but haven’t fully used that paradigm to really apply it to other GI malignancies. And then the art and science of clinical trial design where, again, traditional randomized phase 3 trials might not be the best and most innovative and most expedient way of bringing novel therapeutics to our patients. And so, I thought that all of those sessions were really highlighting different important topics that we deal with day to day.

Additionally, we had a really fantastic keynote lecture from Dr. Kimmie Ng of the Dana-Farber Cancer Institute. She is a world-renowned expert in the early-onset colorectal cancer space, and the timing of her keynote was perfect with the new cancer statistics that came out literally days before GI ASCO that demonstrated this just dramatic rise in early onset GI malignancies as a whole, not just colorectal. And she spoke really in a comprehensive manner not just on clinical approaches, screening approaches, and how to find these patients at an earlier stage, but also kind of gave us a call to action, if you will, in terms of public health initiatives, as well as like I said, clinical care and really thinking outside of the box for how to reach these patients. 

And then, of course, we always have what I think is one of my favorite aspects of the meeting, which are the networking opportunities that include the Trainee and Early Career Networking Luncheon, the Women's Networking Reception, and the Meet the Experts Luncheon where, especially as junior career investigators, you have an opportunity to meet what we think of as the “big names” in GI cancer.

Dr. Shaalan Beg: Absolutely, I remember my first couple of GI ASCO meetings and those were probably the most memorable sessions that I attended as junior faculty as well.  

So let's take a deeper dive into some key abstracts from the meeting. I'd like to begin with Abstract 245. This is the SKYSCRAPER-08 study. It's first-line tiragolumab and atezolizumab with chemotherapy in an Asian patient population with esophageal squamous cell carcinoma. What are your key takeaways from this study? 

Dr. Rachna Shroff: Yeah. This was an exciting study in my opinion in the sense that thinking through how we can build on immunotherapy backbones is obviously a pressing question across the GI cancer space. So this was a phase 3 randomized, double-blinded, placebo-controlled trial that looked specifically at patients with esophageal squamous cell carcinomas. And the study was enrolled fully with an Asian population. It looked at taking the traditional chemotherapy backbone and adding to it an anti-PD-L1 with atezolizumab and an anti-TIGIT with tiragolumab. Again, that proof of principle of using anti-TIGIT and PD-L1 has been looked at across a lot of different GI cancer spaces and we know that the esophageal squamous cell cancers tend to be very immunotherapy responsive. So this was a really important question. 

This involved a number of patients, a little over 460 patients, who were randomized one-to-one to receive the tiragolumab with atezolizumab with the standard paclitaxel and cisplatin, that's used for esophageal squamous versus chemotherapy alone with placebo. And the primary endpoint was independent review of progression-free survival, and overall survival. And so, out of the 461 patients randomized, there was at the primary analysis, a median improvement in progression free survival, from 5.4 months in the control arm to 6.2 months with a tira-paclitaxel plus chemo arm with a hazard ratio of 0.56, highly statistically significant. Similarly the median overall survival was also improved from 11.1 months to 15.7 months again with a hazard ratio of 0.7 and some of the other key efficacy endpoints were also improved with the addition of the anti-TIGIT PD-L1 approach. And importantly, there was not really safety signals that jumped out at us. 

And so, to me, what this means is that, in our patients with esophageal squamous cell carcinoma, we really should be thinking about chemotherapy with immunotherapy as a backbone and how we can build on it. And, you know, I would imagine that it's hard to argue with both the PFS and OS endpoint that adding anti-TIGIT won't necessarily be kind of the new approach to these patients. And importantly, I'll point out that it seems to be a benefit across the subgroups, including PD-1 status, which is always our big question here. I think the only thing to keep in mind is this was an all-Asian population and whether or not that kind of immune profile of the immune responsiveness is different in those patients, but regardless, a positive phase 3 trial.

Dr. Shaalan Beg: It's really exciting to see immune checkpoint inhibitors or immunotherapy beyond PD-1 targeted, CTLA-4 targeted treatments making their way into GI Cancers. 

Dr. Rachna Shroff: Absolutely.

Dr. Shaalan Beg: Sticking with the immunotherapy theme, let's focus on hepatocellular carcinoma. So LBA432, the EMERALD-1 study of transarterial chemoembolization combined with durva with or without bevacizumab looked at people with unresectable hepatocellular carcinoma eligible for embolization. So really a highly anticipated study, I'm wondering what your thoughts are and whether it'll be practice-changing for this field. 

Dr. Rachna Shroff: I was excited to see the press release when it showed that the study was positive, and I think it's because now that we're using immunotherapy in the advanced HCC space, our obvious question is, can we integrate it into multimodality approaches? There are a lot of smaller studies looking at neoadjuvant IO approaches, and in this intermediate stage, unresectable hepatocellular carcinoma patients. We wanted to know if there was a utility to liver directed therapy with immunotherapy. 

So, this was a large study. It was a global study looking at unresectable HCC with preserved Child-Pugh function. But it was Child-Pugh A and up to B7, importantly. And there were 616 patients randomized in a 1:1:1 fashion, with the control arm being just TACE alone. But then, there was also an opportunity for durvalumab with TACE, as well as durvalumab plus bevacizumab with TACE. The patients would receive durvalumab during their TACE treatments and could receive up to four TACE treatments and then subsequently were either continued on durvalumab alone, durvalumab plus bevacizumab, or the placebo. The primary endpoint was progression-free survival, powered specifically to look at TACE versus durvalumab plus TACE. In this study, the primary endpoint was met with a significant improvement in PFS. Median PFS was 15 months versus 8.2 months, with a hazard ratio of 0.77. Most prespecified subgroups demonstrated this benefit. 

Importantly, there was a secondary endpoint looking at durvalumab plus TACE versus TACE alone, and that actually did not show a statistically significant improvement in median PFS from 8.2 months in the control arm to 10.0 months. The overall response rates were slightly higher with the durvalumab plus bevacizumab approach at 43.6%. And importantly in these patients, who oftentimes have a higher burden of disease in the liver, median time to progression is a really important and clinically meaningful endpoint. That was 22 months with the durvalumab plus bevacizumab and TACE versus 10 months for TACE alone.

I would just point out that the overall concern we always have with bevacizumab is the increased risk of bleeding and the treatment-related adverse event profile. Overall, there were no safety signals that emerged from this, with nothing that really, especially in that bleeding risk category, jumped out at us. Of course, we haven't seen the overall survival data yet because we have not seen enough follow-up to really see that number. 

I do think that this is potentially practice-changing, and I think it just demonstrates that there's probably some synergy between anti-VEGF with anti-PD-1, and then the liver-directed treatments. The obvious question for us in the United States is that the vast majority of people are moving away from TACE and towards more radioembolization and what can we extrapolate from this? Does this really tell us much if people are using more of a Y90-based approach? I think those are a lot of the burning questions that most of us have. 

Dr. Shaalan Beg: Yeah, and it's a very interesting direction that the HCC space is taking because we heard in previous meetings, the role of PD-1 inhibition as adjuvant therapy after resection. Now, we have data for local-regionally advanced disease over local-regional treatments. And of course, you already mentioned the data for more advanced disease. So it sounds like immunotherapy may be impacting the management of anyone diagnosed with hepatocellular carcinoma. 

Let's talk about the MONET trial, Abstract 249, which compared thoracoscopic esophagectomy and open esophagectomy for thoracic esophageal cancer. Do you think this is a study which may influence the treatment of patients with thoracic esophageal cancer?

Dr. Rachna Shroff: So, this was, again, I think, a really important question. It was a randomized, controlled phase 3 trial comparing a more minimally invasive approach with TE — thoracoscopic esophagectomy — versus an open approach. This had patients with clinical stage 1-3, excluding T4 thoracic esophageal squamous cell carcinomas. They were randomized 1:1 to the open versus the TE approach, with a primary endpoint of overall survival and an important secondary endpoint of relapse-free survival. 300 patients were randomized, and at the second planned interim analysis, the median follow-up was a little over two and a half years. The 3-year overall survival was 82% in the TE group versus 70.9% in the open group. The DSMC of this trial actually recommended early termination based on the non-inferiority, which is what they were specifically looking at. There was a very statistically significant one-sided p-value for non-inferiority. 

Importantly, the 3-year recurrence-free survival was also markedly better in the TE group versus the open group, with no real notable differences in R0 resection, or a large percentage of patients who needed to be converted from a TE to an open approach, and really not any significant difference in overall postoperative morbidity. I think this just supports the concept that minimally invasive approaches for our patients with GI malignancies can and should be considered. Again, esophageal squamous because they tend to be seen a lot more in Asia, this study was conducted in Japan, but I think that being said, a lot of our surgeons in Europe and in the U.S. are also very amenable to minimally invasive approaches. And I think this just supports the fact that an open approach is not necessary. So, I would think again, that this is something that is implementable and I think will affect the field. 

Dr. Shaalan Beg: Moving on to metastatic cholangiocarcinoma, there have been many FGFR inhibitors that have shown activity and promise and are approved for the management of cholangiocarcinoma with FGFR alteration. But at this ASCO GI, we heard the results of the safety and efficacy of an FGFR1, 2, and 3 inhibitor, tinengotinib, as monotherapy for advanced metastatic cholangiocarcinoma (Abstract 434). How do you see this fitting into the broad picture?

Dr. Rachna Shroff: Yeah, so this was highly anticipated data, primarily because at this point, the FGFR space in cholangiocarcinoma is quite crowded. And so a lot of us were getting sick of the "me-too" drugs. What is really unique about tinengotinib is that, not only is it a selective multikinase inhibitor, but it also, in preclinical models as well as in early phase one trials, demonstrated potent inhibition of patients with FGFR2 fusions and rearrangements who had acquired resistance mutations. So, as we better understand the first generation of FGFR inhibitors and note the resistance mechanisms, these drugs are now being developed to try to circumvent or overcome those. 

This study looked at 4 different cohorts: 1 cohort with FGFR2 fusion patients who had primary progression who never responded to FGFR inhibitors, a second cohort with FGFR2 fusion patients who had progression after primary response, so those with acquired resistance, and then there was non-fusion FGFR alterations because we do know that a number of cholangiocarcinoma patients have other FGFR alterations that are not fusions, and then those with FGFR wild-type. The primary endpoint was objective response rate, with a total of 48 patients enrolled across the four cohorts. And so the 40 patients who were evaluable in the group that had primary resistance, which was the first cohort, there was a response rate was 9.1% and that was partial response, and 31% had tumor reduction with tinengotinib. And similarly in those with acquired resistance, 37.5%, 3 out of 8 patients had a partial response and tumor reductions were noted with an overall disease control rate between those patients with FGFR2 fusions of 94.7%, between those with primary and secondary resistance. 

In the patients who had FGFR alterations, there was 3 out of 9 patients with a partial response and again, tumor reductions were notable across the board and the disease control rate was 88.9%. The FGFR wild-type group, not surprisingly, did not see any partial responses, but interestingly, 75% of these patients had at least disease control, and the median progression-free survival was 5.26 months, again, kind of most notably impressive in the 2 cohorts that included FGFR2 fusions. The toxicity profiles are what we come to expect for FGFR inhibitors and we’ve gotten better at managing those and mitigating some of those so there was really nothing to jump out there.

So there is now an ongoing randomized phase III trial specifically looking at tinengotinib versus physician's choice in patients with FGFR2-altered cholangiocarcinoma after having received prior FGFR inhibitors. So that’s where I think it’s in is for those of us who know that there are multiple drugs in the space, our big question is can we sequence through that? Can we offer multiple FGFR inhibitors in these patients? And I think we are all eagerly anticipating this data as well as the subsequent data to really justify the use of these novel second generation FGFR inhibitors. 

Dr. Shaalan Beg: It's been fantastic to see the evolution of these compounds in precision medicine, or precision oncology at its finest, in terms of understanding mechanisms of resistance and treating refractory disease.  

Let's focus on colorectal cancer. I’ll tell you, there has been a lot of discussion, Dr. Shroff, on social media, on insurance companies sometimes rejecting one biologic or the other based on tumor sidedness. We have talked about tumor sidedness predicting response on this podcast based on data from previous studies. But this year in GI ASCO, Abstract 207 explored the role of tumor genomics and tumor sidedness and they said that it’s tumor genomics, that tumor genomics better explains the differences on outcomes, and it explains it better than sidedness. What does this mean to the field? Because a lot of professional organizations have guidelines that are asking people to now incorporate sidedness. So how does that change based on these results?

Dr. Rachna Shroff: I really commend these authors on leveraging real-world data, and I think we’re getting better and better at recognizing that real world data actually informs our clinical decision making, possibly better than sometimes some of these studies that lead to the guidelines and algorithms that we develop. So this is a perfect example of a little bit cart before horse in trying to understand the way that sidedness and genomics may interplay.  

So this was a study that basically leveraged both the Foundation Medicine and Flatiron Health clinical genomic database and looked at patients with microsatellite stable metastatic colorectal cancer. There were a total of 3,845 patients included in a kind of two-thirds one-third split between left sided and right-sided colorectal cancer. And they found the typical genomic alterations that historically have been thought of more with left-sided colorectal cancer like APC and then more of the RAS BRAF alterations in the right-sided patients. But I think what they really thought and what I think was remarkable is they really looked at the patients and how they received chemotherapy with anti-EGFR or bevacizumab therapies, and they did a multivariate analysis to really see what is driving outcomes. And like you mentioned, what they found was patients in the RAS pathway, those classified as having alterations in the RAS pathway, had less favorable outcomes, while those with APC altered group had more favorable outcomes. And that was regardless of treatment received and sidedness. 

And so when they did an analysis of what was called a “likelihood ratio test,” they found that when genomics was added to the sidedness evaluation, there was an improvement in outcome prediction, but not when sidedness was added to genomics. Like you said, it kind of demonstrates, at least in this mining of real-world data from Flatiron that tumor genomics is probably a better driver and a more important driver in determining outcomes than sidedness. 

I totally agree with you. I would push for us to really kind of bring a little bit of noise to this and to make insurance companies and other companies that are looking at this to think through this a little bit more and make sure that we’re putting all of the data together in a comprehensive passion before making the treatment plans and determinations.

Dr. Shaalan Beg: The last abstract I'd like to ask you about is Abstract 117, the NEST-1 trial. This study looked at neoadjuvant botensilimab and balstilimab for resectable mismatch repair proficient and deficient colorectal cancer, both MSS and MSI. What are your key takeaways from this study? 

Dr. Rachna Shroff: This is another study that is demonstrating that there may potentially be a role for immunotherapy in microsatellite stable patients. I will make the caveat that this was a single-arm study that really was looking at feasibility safety, with efficacy as a secondary endpoint. The combination of bot-bal in the neoadjuvant space for colorectal cancer patients, they received one dose of boten and two fixed doses of bal two weeks apart and then were taken to surgery. They limited the number of patients and out of the 12 patients that were enrolled, they limited the number of mismatch repair deficient patients. So to your point, they allowed both, but they wanted to make sure it was not just MSI-high patients.

What they basically found is that it was safe and did not delay surgery or increase risks of adverse events. But importantly, there was significant regression of tumor noted. And some interesting spatial biology analyses demonstrated potentially novel mechanisms of action, especially in the MSS population, and that ctDNA reductions correlated with pathologic response. There were a lot of different things that they were looking at, basically suggesting that bot-bal is safe and can be used in both mismatch repair–deficient and proficient patients with colorectal cancer. And now importantly, they’ve added some additional cohorts and expanding the study. As I mentioned, this is right now just 12 patients, but does definitely have a provocative result. 

Dr. Shaalan Beg: Thanks so much, Dr. Shroff. 

Finally, the role of cell-free DNA (cfDNA) in GI cancers has been an exciting and important development in our field. There's tremendous data that emerged at the GI meeting, and we have decided to do a separate ASCO Daily News Podcast dedicated to ctDNA. So listeners, please look out for our coverage of key studies on ctDNA in GI cancers very soon here on the ASCO Daily News Podcast. 

Many thanks, Dr. Shroff, for sharing your insights with us today and for your great work in building a robust GI meeting this year. Thank you very much.

Dr. Rachna Shroff: Thank you so much.

Dr. Shaalan Beg: And thank you to all our listeners for your time today. You'll find links to the abstracts discussed on the transcript of this episode. Finally, if you value the insights that you hear on the ASCO Daily News Podcast, please take a moment to rate, review, and subscribe wherever you get your podcasts.

Disclaimer:

The purpose of this podcast is to educate and inform. It is not a substitute for professional medical care and is not intended for use in the diagnosis or treatment of individual conditions. Our guests on this podcast express their own opinions, experiences, and conclusions. These statements do not necessarily reflect the views of ASCO. The mention of any product, service, organization, activity, or therapy should not be construed as an endorsement by ASCO.

 

Find out more about today’s speakers:

Dr. Shaalan Beg

@ShaalanBeg

Dr. Rachna Shroff

@rachnatshroff

 

Follow ASCO on social media: 

@ASCO on Twitter 

ASCO on Facebook 

ASCO on LinkedIn 

 

Disclosures:

Dr. Shaalan Beg:

Employment: Science 37

Consulting or Advisory Role: Ipsen, Array BioPharma, AstraZeneca/MedImmune, Cancer Commons, Legend Biotech, Foundation Medicine

Research Funding (Inst.): Bristol-Myers Squibb, AstraZeneca/MedImmune, Merck Serono, Five Prime Therapeutics, MedImmune, Genentech, Immunesensor, Tolero Pharmaceuticals

 

Dr. Rachna Shroff:

Consulting or Advisory Role: Exelixis, Merck, QED Therapeutics, Incyte, Astra Zeneca, Taiho Pharmaceutical, Boehringer Ingelheim, SERVIER, Genentech, Basilea

Research Funding: Pieris Pharmaceuticals, Taiho Pharmaceutical, Merck, Exelixis, QED Therapeutics, Rafael Pharmaceuticals, Bristol-Myers Squibb, Bayer, Immunovaccine, Seagen, Novocure, Nucana, Loxo/Lilly, Faeth Therapeutics

Drs. Neeraj Agarwal and Todd Morgan discuss CONTACT-02, KEYNOTE-564, CheckMate-67T, and other notable studies featured at the 2024 ASCO Genitourinary Cancers Symposium, as well as additional key abstracts in prostate, kidney, and bladder cancers that will significantly influence clinical practice.

TRANSCRIPT

Dr. Neeraj Agarwal: Hello, and welcome to the ASCO Daily News Podcast. I'm Dr. Neeraj Agarwal, the director of the Genitourinary Oncology Program and professor of medicine at the Huntsman Cancer Institute at the University of Utah, and editor-in-chief of ASCO Daily News. Today, we'll be discussing practice-changing abstracts and other key advances in GU oncology featured at the 2024 ASCO Genitourinary Cancers Symposium.

Joining me for this discussion is Dr. Todd Morgan, the chair of this year's ASCO GU. Dr. Morgan is a urologic surgeon, chief of urologic oncology at Michigan Medicine, and a professor of urology at the University of Michigan. Our full disclosures are available in the transcript of this episode, and the disclosures of all guests on the podcast can be found at asco.org/DNpod. Todd, thank you for joining us today.

Dr. Todd Morgan: Thanks so much, Neeraj. It's an honor to be here and I'm just thrilled to be able to do this with you.

Dr. Neeraj Agarwal: Thank you. So, the GU meeting showcased significant advancements across the spectrum of GU malignancies. Can you tell us about the hot topics that captured the headlines this year? What did you find exciting this year at the ASCO GU Symposium?

Dr. Todd Morgan: The theme of this year's meeting was "20 Years of Advancing Science and Transforming Patient Care," and this reflected ASCO GU's incredible milestone in GU cancer research over the last 2 decades. We were thrilled to welcome over 5,200 attendees from over 70 countries, and, believe it or not, there were more than 875 abstract submissions, compared to more than 300 in the meeting's first year. Most of the participants were present in person and that was fantastic. It enabled great networking opportunities and opportunities for experts, trainees, and mentees to exchange knowledge and ideas. Without a doubt, ASCO GU remains the annual meeting in our field, and it's amazing to hear the breadth and depth of the state-of-the-art science that's presented at this meeting, and so much of it impacts patient care the second that you return home.

Additionally, the meeting's focus on diversity and interactivity, networking, multidisciplinary collaboration, and evidence-based care were absolutely phenomenal from my standpoint. We had a lunch session for women's networking that was a huge success—the first time we've done that. The keynote lecture by Dr. Cheryl Lee that talked about ensuring adequate representation in clinical trials was a huge hit, and we had tremendous positive feedback from that lecture. There were also multiple featured sessions on different diagnostic and therapeutic challenges in localized, recurrent, and advanced GU cancers. And, Neeraj, my personal favorite during the symposium is always the Trainee and Early-Career Networking Luncheon on the first day and then the additional networking luncheons on the 2 following days. I had great conversations with a ton of trainees and junior faculty, and I feel so fortunate for the opportunity to get to know the future superstars in our field.

So I’d like to kick it back to you for a second because the first day started with a focus on prostate cancer and some of the key clinical trials. A great example is Abstract 17, which was the second oral presentation delivered, and really congratulations to you, Neeraj, on sharing the exciting data from the CONTACT-02 trial which we were eagerly awaiting. And I'd love to get your thoughts on the data that you presented. Could you tell us more about that trial?

Dr. Neeraj Agarwal: Yes, Todd, I agree with you. It was such an exciting conference overall, and thank you for your leadership of this conference.

So let's talk about the CONTACT-02 trial. It was a phase 3 randomized trial assessing the combination of cabozantinib and atezolizumab versus a second NHT in patients with metastatic castration-resistant prostate cancer after progression on one NHT. This patient population had to have extrapelvic soft tissue metastases, which could be liver metastases, lung metastases, or lymph nodal metastases, and about up to a quarter of patients had liver metastases. And overall, this was a high-risk patient population which was randomized to, as I said, cabozantinib plus atezolizumab versus a second line NHT. And these patients had received a prior NHT, mostly in the mCRPC setting.

 The co- or dual primary endpoints were overall survival and progression-free survival (PFS). And a unique thing was that PFS was assessed only by RECIST 1.1 because, as per our discussions with regulatory authorities, the trial was focused on soft tissue metastases because of questions in the past that cabozantinib can affect bone lesions in an artifactual fashion, possibly concerns. That’s why the PCWG 3 criteria were not used as the primary endpoint, but, of course, indeed used as another key endpoint, so we have information on both. Anyway, coming back to the endpoint 1:1 randomization. The randomization was stratified by presence or absence of liver metastases, prior docetaxel chemotherapy, and the setting in which NHT was given (mCSPC or CRPC).

The PFS or primary endpoint was significantly improved with a 35% reduction in risk of progression or death with the cabozantinib-atezolizumab combination versus second NHT. And there was a trend for overall survival, with a hazard ratio of 0.79 favoring the cabozantinib-atezolizumab combination. Interestingly, all subgroups benefitted, regardless of age, region, site of metastases, but we decided to choose three clinical subgroups of interest such as patients with liver metastases, patients with prior docetaxel chemotherapy in the castration-sensitive setting, and bone metastases, and all these subgroups seemed to be benefitting with the strongest signal in the liver metastasis subgroup, with a 57% reduction in risk of progression or death, which I would argue we have never seen with any combination or any regimen in the metastatic prostate cancer setting yet, barring some targeted therapies in very selected patients. But overall, across the non-biomarker-selected patients, we have never seen this kind of signal.

Toxicity — no discussion is complete without discussing toxicity, so I would like to highlight that. Safety signal — there were no new safety signals. The most common grade 3-4 adverse events were hypertension in 7%, anemia in 6%, which were similar in both arms, and, of course, diarrhea and fatigue in 4% each. And if we look at the secondary endpoints, such as time to chemotherapy and time to symptomatic skeletal events, they tended to favor the cabozantinib-atezolizumab. To sum it up, cabozantinib-atezolizumab showed a significant PFS benefit, with a 35% reduction in risk of progression or death, with a trend for overall survival in this patient population with an unmet need.

So thank you so much, Todd, for allowing me to summarize the results of this trial.

Dr. Todd Morgan: Yeah, wow. That's so impressive, and not surprising that you could so fluidly go right through all that data. Amazing. We heard some discussion of the NHT control arm in this trial. Could you discuss that for a bit? Because it obviously has implications on the similar control arm of other ongoing trials in this setting.

Dr. Neeraj Agarwal: Absolutely. Pretty much all trials, every trial which has recently been reported or started in metastatic castrate-resistant prostate cancer have a similar second NHT arm. Whether there were multiple immunotherapy trials which we have just reported, or new trials which are starting or just started enrolling patients. And the reason for that is no randomized trial has ever shown superiority of docetaxel chemotherapy over a second NHT after failure of prior NHT in the mCRPC setting. That's number one. If you look at NHT as a control, it is accepted by health authorities globally with multiple recent trials which are just starting also having NHDR and it would not have been possible without the approval of global regulatory authorities across the world.

 Then, if you look at the recently reported trial in the mCRPC setting with prior treatment with an NHT, there is an indication that chemotherapy may not be superior to NHT. For example, in the KEYNOTE-641 trial in patients with mCRPC with prior NHT, randomizing patients to enzalutamide plus pembrolizumab versus enzalutamide, the median PFS with enzalutamide was 9 months. This is very similar with docetaxel in patients randomized to docetaxel plus pembrolizumab versus docetaxel; the median PFS with docetaxel is 8 months or 8.3 months. And lastly, if you really want to have a comparison of chemotherapy with NHT which has been done after progression on NHT and docetaxel chemotherapy, so later line of mCRPC setting, that is the CARD trial, as you can imagine, cabazitaxel versus NHT, especially in patients with visceral metastasis, which was the point of discussion. For example, people may not feel comfortable randomizing patients to NHT compared to taxane. The hazard ratio for PFS supporting cabazitaxel was 0.79, so almost a 0.80 PFS hazard ratio, which we have never seen turning out to be a clinically significant benefit.

So, if you combine all these data together, I think it was absolutely acceptable to us as investigators to have a second NHT as the control arm. And of course, when we are consenting the patient, we have to keep alternatives in mind, and we do talk about those alternatives with the patients. And if alternatives seem more applicable, we should not be talking to patients about those clinical trials or a given clinical trial in the clinic. I'm glad you brought this up, Todd, because this control NHT arm is not an issue with this trial, but all trials which should be presented in GU ASCO in the future meetings in the coming years. So, thank you.

Dr. Todd Morgan: Yeah, thank you. It's such an important topic and controversy at some level, but it's a difficult problem to think about and obviously highly relevant to all the trials that we're looking at. Congrats again on that trial, that's tremendous. There was another important randomized phase 3 trial and it covers radiotherapy in patients with high-risk localized prostate cancer. Can you give us your insights on that one?

Dr. Neeraj Agarwal: Yeah, Todd, I think you are referring to LBA259, titled "Long-term Results of Dose Escalation of Radiation Therapy from 70 Gy to 80 Gy Combined with Long-term Androgen Deprivation Therapy in High-risk Prostate Cancer: The GETUG-AFU 18 Randomized Trial." As you mentioned, in this randomized phase 3 trial, Dr. Christophe Hennequin and colleagues randomized patients with high-risk prostate cancer, which means they had to have either clinical stage T3 or T4 disease, or PSA ≥20 nanograms per milliliter, or a Gleason score between 8 and 10. These patients were randomized to receive ADT for 3 years combined with either dose-escalated intensity-modulated radiotherapy. So, I’d like to highlight, this was in the context of IMRT in the dose of 80 Gy or a conventional dose of 70 Gy. Now, you can argue that more people are using more than 70 Gy nowadays, but across the world, the conventional dose is still considered 70 Gy. So, 80 Gy versus 70 Gy were tested.

Patients also had to have negative lymph node status on CT scans and MRI. The primary endpoint was biochemical progression-free survival or clinical progression-free survival at 5 years following the ASTRO Phoenix definition. Secondary endpoints – and these are quite important secondary endpoints – include overall survival, acute and late toxicity, and quality of life. The best part is that this trial met its primary endpoint with a 44% reduction in risk of biochemical or clinical progression or death in the dose-escalation radiotherapy arm compared with the conventional radiotherapy arm. Interestingly, a significant 52% improvement in prostate cancer-specific survival and a 39% improvement in overall survival was observed in the dose-escalated arm. So, 80 Gy continued to be superior to 70 Gy IMRT across the primary and secondary endpoints. Now, the best part is, regarding the toxicity profile, there was no significant difference between the 2 arms, with 78% of patients in the higher dose arm and 76% of patients in the conventional arm experiencing grade 2 or more toxicities.

Dr. Todd Morgan: Great summary and really important, great news for our patients. Of course, it's a slightly different setting as it's high-risk localized prostate cancer. I checked in with our radiation oncologists at the University of Michigan after that [presentation] because I couldn't remember exactly where we are in terms of dose on these patients. And they were like, “Yeah, we've been doing 80 to 90 Gy for several years,” so it's great having this data to support that. And I think, as you said, the field at many centers has already moved that way.

And again, the key takeaway from this abstract would be that IMRT, in combination with long-term androgen deprivation therapy, is effective and safe and increases not only the biochemical or clinical PFS rate, but also the cancer-specific survival and overall survival, again, in high-risk localized prostate cancer patients. And it does not appear to increase long-term toxicity. So really important.

It'd be great to switch gears and discuss kidney cancer, if that's okay, and talk about some key abstracts in that field. What do you think?

Dr. Neeraj Agarwal: There were so many exciting data in all cancers, which is amazing. So, Todd, could tell us about the LBA359, which I thought was one of the most impactful abstract presentations in the ASCO GU this year. It was titled, “Overall Survival Results from the Phase 3 KEYNOTE-564 Study of Adjuvant Pembrolizumab Versus Placebo for Treatment of Clear Cell Renal Cell Carcinoma (ccRCC)."

 

Dr. Todd Morgan: Yeah, this was a really big moment in our field, complete with a mid-presentation round of applause that was well deserved. And so this abstract was presented by Dr. Toni Choueiri from Dana-Farber Cancer Institute, and it included patients with clear cell renal cell carcinoma at intermediate high or high risk of recurrence, meaning that they had positive nodal disease or negative nodal disease with PT 2 and grade 4, or sarcomatoid features, or stage PT 3 or 4. These patients underwent nephrectomy with or without metastasectomy less than 12 weeks before randomization and had not received prior systemic therapy for clear cell RCC. Patients were randomized to receive either pembrolizumab 200 milligrams or placebo IV every three weeks for at least 17 cycles, or until disease recurrence, intolerable toxicity, or withdrawal of consent. Disease-free survival by investigator assessment was the primary endpoint, and overall survival was a key secondary endpoint. In this abstract, Dr. Choueiri and colleagues report results of the third prespecified interim analysis with a median follow-up of around 57 months in 496 patients receiving pembrolizumab and 498 patients receiving placebo.

So, just as a reminder to the audience here, the first interim analysis reported at a median follow-up of 24 months and showed a significant reduction of 32% in the risk to recurrence or death in patients in the pembrolizumab arm. Then subsequently in November of 2021, the FDA approved pembrolizumab for the adjuvant treatment of patients with RCC who are at intermediate high or high risk of recurrence following nephrectomy or following nephrectomy and resection of metastatic lesions. At that time, though, overall survival data were still immature. So, at the third prespecified interim analysis with a median follow-up of around 57 months, pembrolizumab showed, for the first time in an adjuvant RCC setting, improved overall survival with a 38% reduction in the risk of death. The estimated OS rate at 48 months was 91.2% with pembrolizumab and 86% with placebo. Furthermore, the OS benefit was observed across key subgroups, including patients with non-metastatic disease, patients with metastatic but no evidence of disease, patients with PDL-1 combined positive score less than or greater than or equal to one, and patients with presence or absence of sarcomatoid features. In each of these subgroups, the forest plot looks really impressive. And the DFS benefit was similar to previously reported interim analyses with a hazard ratio of 0.72. Also, no new safety signals with pembrolizumab were observed so just tremendous data.

Dr. Neeraj Agarwal: Thank you, Todd, for such a great summary of these very important results. So the key message from this abstract, as you said, is that after a median follow-up of around 57 months, which is a long follow-up, adjuvant pembrolizumab demonstrates a statistically significant and clinically meaningful improvement in overall survival versus placebo in patients with RCC at high risk of disease recurrence after surgery. And this is, by the way, the first phase 3 study to show improved overall survival with any adjuvant therapy in RCC. Basically, this means we should continue to use adjuvant pembrolizumab or at least bring it up in our discussion with our patients who are in a similar situation with high-risk RCC after surgery. So this is great news overall.

Todd, there was another kidney cancer abstract, LBA360, which compared, interestingly, subcutaneous nivolumab with intravenous nivolumab in patients with metastatic renal cell carcinoma. Could you please give us your insight about this abstract?

 

Dr. Todd Morgan: Sure. Really interesting study. Really interesting data that were presented. So as you mentioned, CheckMate 67T was a multicenter, randomized, open-label phase three study led by Dr. Saby George and colleagues that evaluated pharmacokinetics and objective response rate non-inferiority of subcutaneous nivolumab versus IV nivolumab in patients with locally advanced or metastatic clear cell RCC. So patients with measurable disease that progressed during or after 1 to 2 prior systemic regimens and who did not receive a prior immuno-oncology treatment were randomized 1-1 to receive either subcutaneous nivolumab 1200 milligrams every 4 weeks or IV nivolumab 3 milligrams per kilogram every two weeks until disease progression, unacceptable toxicity, withdrawal of consent, completion of two years of treatment, or death.

The coprimary pharmacokinetics endpoints for non-inferiority testing were time-average serum concentration over the first 28 days and minimum serum concentration at steady state determined by a population pharmacokinetics analysis. A key secondary endpoint was objective response rate by independent review. So in 248 patients receiving subcutaneous nivolumab and 247 patients receiving IV nivolumab, non-inferiority for the coprimary pharmacokinetics and key-powered secondary objective response rate endpoints were met. The relative risk ratio for objective response rate was 1.33. The median PFS by independent review was 7.23 months in the subcutaneous group and 5.65 months in the IV group. Treatment-related serious adverse events occurred in 6.5% of patients in each group, and study drug toxicity led to 3 deaths in the subcutaneous group and 1 death in the IV group. These results could support using subcutaneous nivolumab as a new option to improve healthcare efficiency, especially since the average injection time with subcutaneous nivolumab was less than 5 minutes. I think we all know what issues are going on in infusion beds across the country, including, I'm sure, your center and mine.

Dr. Neeraj Agarwal: Yes, absolutely. I think this is great news for our patients, Todd. Thank you. This shows that we are not only improving therapeutic options and diagnostic tools, but maybe we're also on the right track towards more practical administration routes, assisting in addressing the treatment burden and improving the efficiencies of healthcare systems. We love to have this option available for our patients, especially those who are pressed for time. So, Todd, would you like to move on to bladder cancer now?

 Dr. Todd Morgan: Yeah, Neeraj, that'll be fantastic. I'm sure listeners would love to hear more about LBA530. Could you tell us more about this one, Neeraj?

Dr. Neeraj Agarwal: Of course. I think this abstract is titled "Enfortumab Vedotin in Combination with Pembrolizumab Versus Chemotherapy in Previously Untreated, Locally Advanced or Metastatic Urothelial Carcinoma: Subgroup Analysis Results from EV-302," which was a global phase three study and was presented by Dr. Michiel Van Der Heijden. As our audience may recall, the EV-302 trial was presented at the ESMO 2023 meeting by Dr Tom Powles and the results were very exciting where, for the first time, a combination outperformed traditional gemcitabine-cisplatin chemotherapy. In this trial, patients with previously untreated with metastatic advanced urothelial carcinoma were randomized 1-1 to receive a 3-week cycle of a combination of enfortumab vedotin, which, as we know, is an antibody-drug conjugate targeting nectin-4 expressed on the cancer cells and pembrolizumab, which is a PD-1 inhibitor, versus gemcitabine and cisplatin or carboplatin, which were, until recently, the standard of care in this setting, and continue to be so in many countries in the world. The combination of enfortumab and pembrolizumab reduced the risk of progression or death by 55% and reduced the risk of death by 53% in the overall population. So consistent decrease in the hazard ratios for PFS and OS, and consistent improvement in overall survival and PFS in that previously reported presentation in the ESMO 2023.

Now, based on these results, this combination was recently approved by the FDA in December 2023 for patients with advanced or metastatic urothelial carcinoma. So now the abstract, which was presented at the ASCO GU 2024 meeting, reported the results of a prespecified subgroup analysis. Select secondary endpoints included objective responses, duration of response, and safety. In 442 patients receiving the combination of enfortumab vedotin plus pembrolizumab, and a similar number of patients receiving chemotherapy both PFS and OS were higher for the combination of EV and pembro among prespecified subgroups such as race, platinum eligibility, PDL-1 expression, metastatic site, involvement of the liver or kidney function.

Interestingly, the combination of EV and pembro reduced the risk of death by 53% in patients with visceral metastasis and 54% in patients with node-only metastasis. The improvement in PFS seems to be consistent regardless of the site of metastasis. In patients with moderate to severe renal function, the risk of death was reduced by 50% in patients receiving combination therapy. This is one of the best findings of these results because we always face challenges in treating patients with suboptimal kidney function and we cannot use cisplatin. Overall, EV plus pembro continues to show superior efficacy compared to platinum-based regimens across subgroups across the subgroups across the site of metastasis regardless of kidney function and so on.

Dr. Todd Morgan: Yeah, just amazing data. I love hearing you spell it out like that. So, thank you again for the opportunity for me to sit here with you and listen to you talk about these data. It's impressive that we have been able to expand our therapeutic arsenal for urothelial carcinoma with an immune-targeting regimen that can spare our patients potential side effects of chemotherapy. What would your final takeaway on this abstract be?

Dr. Neeraj Agarwal: I agree with you, Todd. I would add that the OS benefit was consistently observed across these select prespecified subgroups, including those historically associated with poor prognosis. The results of this new analysis support the finding of primary results, which indicate that EV plus pembro is a potentially new standard of care for patients with newly diagnosed, locally advanced, or metastatic urothelial carcinoma.

Before we wrap up the bladder cancer session and the podcast, Todd, could you please give us insights about LBA531?

Dr. Todd Morgan: Yeah, absolutely. I loved getting to hear this abstract presented. This one is titled “Ambassador,” known as the AMBASSADOR trial aligns A031501, a phase 3 randomized adjuvant study of pembrolizumab in muscle-invasive and locally advanced urothelial carcinoma versus observation, that was presented by Dr. Andrea Apolo. It's an open-label, randomized, phase 3 trial that included patients with muscle-invasive urothelial carcinoma of the bladder, upper tract, or urethra. Eligible patients had pathologic tumor stage T2 or greater and/or positive pathologic nodal disease or positive margins at surgery following neoadjuvant chemotherapy, or patients with pathologic tumor stage T3 or greater and/or positive pathologic nodal disease or positive margins at surgery without prior neoadjuvant chemotherapy, and who were cisplatin ineligible or declined adjuvant cisplatin-based therapy. These patients were randomized one to one to either receive pembrolizumab 200 milligrams every 3 weeks for 1 year or observation.

The dual primary endpoints were disease-free survival and overall survival. Secondary objectives included evaluation of DFS and OS in PDL-1 positive and negative patients and assessing safety. A total of 354 patients were enrolled to receive pembrolizumab and 348 to the observation arm, and 21% of the patients in the observation arm received a subsequent immune checkpoint inhibitor. At a median follow-up of 22.3 months for DFS, the median disease-free survival in the pembrolizumab arm was 29 months, while it was only 14 months in the observation arm with a hazard ratio of 0.69. At the interim analysis, OS data showed only a trend toward better outcomes in the pembrolizumab arm, which did not, however, reach statistical significance, with a median of 50.9 months in the pembrolizumab arm and 55.8 months in the observation arm with a hazard ratio of 0.98. These results could nevertheless have been impacted by the subsequent treatment of patients in the observation arm with an immune checkpoint inhibitor, especially after the FDA approval of nivolumab in 2021 for patients with muscle-invasive urothelial carcinoma, based on results of the CheckMate 274 trial. In terms of the safety profile, grade three or more adverse events occurred in 48.4% of patients in the pembrolizumab arm and 31.8% of patients in the observation arm.

Dr. Neeraj Agarwal: That's great, Todd. This is such a great summary of this trial, and this is exciting news for our patients with muscle-invasive urothelial carcinoma. I'm hoping that pembrolizumab will be another option for our patients when we are discussing adjuvant immunotherapy in the clinic, moving forward very soon.

With that, we have covered several abstracts addressing prostate, bladder, and kidney cancer, significantly influencing our medical practices, at least at the current moment or in the near future. Todd, thank you for sharing your insights today. These are undoubtedly exciting updates for all members of the GU oncology community, and we are grateful for your valuable contribution to the discussion. Many thanks.

Dr. Todd Morgan: Thanks, for having me, Neeraj; this was really fun. I'm just really proud and excited to still be part of this field, to be part of the GU oncology field, and it continues to be exciting for all the folks who are coming up.

Dr. Neeraj Agarwal: Indeed. And thank you to our listeners for joining us today. You will find links to the abstracts discussed today on the transcript of this episode. Finally, if you value the insights that you hear on the ASCO Daily News Podcast, please take a moment to rate, review, and subscribe wherever you get your podcasts. Thank you very much.

 

Disclaimer:

The purpose of this podcast is to educate and inform. This is not a substitute for professional medical care and is not intended for use in the diagnosis or treatment of individual conditions. Guests on this podcast express their own opinions, experience, and conclusions. Guest statements on the podcast do not express the opinions of ASCO. The mention of any product, service, organization, activity, or therapy should not be construed as an ASCO endorsement.

 

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Dr. Neeraj Agarwal

@neerajaiims

 

Dr. Todd Morgan

@wandering_gu

 

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Disclosures:   

Dr. Neeraj Agarwal:   

Consulting or Advisory Role: Pfizer, Bristol-Myers Squibb, AstraZeneca, Nektar, Lilly, Bayer, Pharmacyclics, Foundation Medicine, Astellas Pharma, Lilly, Exelixis, AstraZeneca, Pfizer, Merck, Novartis, Eisai, Seattle Genetics, EMD Serono, Janssen Oncology, AVEO, Calithera Biosciences, MEI Pharma, Genentech, Astellas Pharma, Foundation Medicine, and Gilead Sciences   

Research Funding (Institution): Bayer, Bristol-Myers Squibb, Takeda, Pfizer, Exelixis, Amgen, AstraZeneca, Calithera Biosciences, Celldex, Eisai, Genentech, Immunomedics, Janssen, Merck, Lilly, Nektar, ORIC Pharmaceuticals, Crispr Therapeutics, Arvinas  

Dr. Todd Morgan:

Consulting or Advisory Role: Myriad Genetics, MDxHealth, TerumoBCT

Research Funding (Institution): Prostate Cancer Foundation, National Institutes of Health, Department of Defence, GenomeDX Biosciences, Myriad Genetics, MDxHealth

 

Drs. Neeraj Agarwal and Jeanny Aragon-Ching discuss several key abstracts to be presented at the 2024 ASCO GU Cancers Symposium, including sequencing versus upfront combination therapies for mCRPC in the BRCAAway study, updates on the CheckMate-9ER and CheckMate-214 trials in ccRCC, and a compelling real-world retrospective study in mUC of patients with FGFR2 and FGFR3 mutations.

TRANSCRIPT

Dr. Neeraj Agarwal: Hello, everyone, and welcome to the ASCO Daily News Podcast. I'm Dr. Neeraj Agarwal, your guest host of the podcast today. I am the director of the Genitourinary Oncology Program and a professor of medicine at the University of Utah’s Huntsman Cancer Institute, and editor-in-chief of ASCO Daily News. I am delighted to welcome Dr. Jeanny Aragon-Ching, a genitourinary oncologist and the clinical program director of Genitourinary Cancers at the Inova Schar Cancer Institute in Virginia. Today, we will be discussing key posters and oral abstracts that will be featured at the 2024 ASCO Genitourinary Cancer Symposium, which is celebrating 20 years of evolution in GU oncology this year. 

You will find our full disclosures in the transcript of this podcast, and disclosures of all guests on the podcast at asco.org/DNpod. 

Jeanny, it’s great to have you on the podcast today to highlight some key abstracts for our listeners ahead of the GU meeting.

Dr. Jeanny Aragon-Ching: Thank you so much, Neeraj. It’s an honor to be here.

Dr. Neeraj Agarwal: Jeanny, as you know, this year we are celebrating the 20th anniversary of the ASCO GU Cancers Symposium, and judging from this year's abstracts, it’s clear that this meeting continues to play a major role in advancing GU cancer research.

Dr. Jeanny Aragon-Ching: Indeed, Neeraj. This year's abstracts reflect the important strides we have made in GU cancers. So, let's start with the prostate cancer abstracts. What is your takeaway from Abstract 19 on BRCAAway, which will be presented by Dr. Maha Hussein, and of which you are a co-author? As our listeners know, several PARP inhibitor combinations with second-generation androgen receptor pathway inhibitors, or ARPIs, have recently been approved as first-line treatment for patients with metastatic castrate-resistant prostate cancer, or metastatic CRPC, and the question of sequencing PARP inhibitors and ARPIs instead of combining them has emerged. From that perspective, the results of the BRCAAway trial are very important. Can you tell us a little bit more about this abstract, Neeraj? 

Dr. Neeraj Agarwal: I totally agree with you, Jeanny. The BRCAAway study attempts to answer the crucial questions regarding sequencing versus upfront combination of therapies in the mCRPC setting. It is a phase 2 trial of abiraterone versus olaparib versus abiraterone with olaparib in patients with mCRPC harboring homologous recombination repair mutations. Enrolled patients had mCRPC disease and no prior exposure to PARP inhibitors or ARPIs or chemotherapy in the mCRPC setting and had BRCA1 or BRCA2 or ATM mutations. As previously mentioned, these patients were randomized to 3 arms: abiraterone monotherapy at 1000 milligrams once daily, or olaparib monotherapy at 300 milligrams twice daily, or the combination of abiraterone and olaparib. The primary endpoint was progression-free survival per RECIST 1.1 or Prostate Cancer Working Group 3-based criteria or clinical assessment or death, so, whichever occurred first was deemed to be progression.  

Secondary endpoints included measurable disease response rates, PSA response rate, and toxicity. This was a relatively small trial with 21 patients in the combination arm, 19 patients in the abiraterone monotherapy arm, and 21 patients in the olaparib monotherapy arm. It should be noted that 26% of patients had received docetaxel chemotherapy in the hormone-sensitive setting, and only 3% of patients had any prior exposure to an ARPI, and these were darolutamide or enzalutamide or in the non-metastatic CRPC setting. 

The results are very interesting. The median progression-free survival was 39 months in the combination arm, while it was 8.4 months in the abiraterone arm and 14 months in the olaparib arm. An important finding that I would like to highlight is that crossover was also allowed in the monotherapy arms. Of the 19 patients receiving abiraterone, 8 crossed over to receive olaparib, and of the 21 patients receiving olaparib, 8 crossed over to the abiraterone arm. The median PFS from randomization was 16 months in both groups of patients who received abiraterone followed by olaparib or those who received olaparib followed by abiraterone. This is striking when compared to 39 months in patients who started therapy with the combination therapy of abiraterone with olaparib.

Dr. Jeanny Aragon-Ching: Thank you so much for that wonderful summary, Neeraj. So the key message from this abstract is that combining olaparib and abiraterone upfront seems to be associated with improvement in PFS compared to just sequencing those agents.

Dr. Neeraj Agarwal: Exactly, Jeanny. I would like to add that these results are even more important given that in real-world practice, only half of the patients with mCRPC receive a second-line treatment. Based on these results, upfront intensification with a combination of an ARPI plus a PARP inhibitor in the first-line mCRPC setting seems to have superior efficacy compared to sequencing of these agents.

Dr. Jeanny Aragon-Ching: Thank you so much. Now, moving on to a different setting in prostate cancer, there were a couple of abstracts assessing transperineal biopsy compared to the conventional transrectal biopsy for the detection of prostate cancer. So let's start with Abstract 261. Neeraj, can you tell us a little bit more about this abstract?

Dr. Neeraj Agarwal: Sure, Jeanny. So, in Abstract 261 titled "Randomized Trial of Transperineal versus Transrectal Prostate Biopsy to Prevent Infection Complications," Dr. Jim Hugh and colleagues led a multicenter randomized trial comparing these 2 approaches, so, transperineal biopsy without antibiotic prophylaxis with transrectal biopsy with targeted prophylaxis in patients with suspected prostate cancer. The primary outcome was post-biopsy infection. Among the 567 participants included in the intention-to-treat analysis, no infection was reported with the transperineal approach, while 4 were detected with the transrectal approach, with a p-value of 0.059. The rates of other complications, such as urinary retention and significant bleeding, were very low and similar in both groups. The investigators also found that detection of clinically significant cancer was similar between the 2 techniques and concluded that the transperineal approach is more likely to reduce the risk of infection without antibiotic prophylaxis.

Dr. Jeanny Aragon-Ching: So the key takeaway from this abstract sounds like office-based transperineal biopsy is well-tolerated and does not compromise cancer detection, along with better antibiotic stewardship and health care cost benefits. 

Moving on to Abstract 273, also comparing these two approaches, what would be your key takeaway message, Neeraj? 

Dr. Neeraj Agarwal: In this Abstract 273, titled "Difference in High-Risk Prostate Cancer Detection between Transrectal and Transperineal Approaches," Dr. Semko and colleagues found that the transperineal biopsy based on MRI fusion techniques was also characterized by a higher possibility of detecting high-risk prostate cancer and other risk factors as well, such as perineural and lymphovascular invasion or the presence of cribriform pattern, compared to the conventional transrectal method.

Dr. Jeanny Aragon-Ching: Thank you, Neeraj. So we can see that the transperineal approach is gaining more importance and could be associated with more benefits compared to the conventional methods.  

Let's now switch gears to kidney cancer, Neeraj.

Dr. Neeraj Agarwal: Sure, Jeanny. Let's start by highlighting Abstract 361, which discusses patient-reported outcomes of the LITESPARK-005 study. So what can you tell us about this abstract, Jeanny? 

Dr. Jeanny Aragon-Ching: Thank you, Neeraj. So as a reminder to our listeners, based on the LITESPARK-005 trial, it was a Phase 3 trial looking at belzutifan, which is an inhibitor of hypoxia inducible factor 2 alpha or I’ll just call HIF-2 alpha for short, was very recently approved by the FDA as a second-line treatment option for patients with advanced or metastatic clear cell renal cell carcinoma after prior progression on immune checkpoint and antiangiogenic therapies. The title of Abstract 361 is "Belzutifan versus Everolimus in Patients with Previously Treated Advanced RCC: Patient-Reported Outcomes in the Phase 3 LITESPARK-005 Study," and this will be presented by Dr. Tom Pells at the meeting. At a median follow-up of 25.7 months, the median duration of treatment with belzutifan was 7.6 months, while it was only 3.9 months with everolimus. At the time of data cutoff date for the second interim analysis, 22.6% of patients remained on belzutifan while only 5% remained on everolimus. In the quality of life questionnaires, the time of deterioration to various quality of life scores, as assessed by standardized scales, was significantly longer in patients randomized to the belzutifan arm compared to those in the everolimus arm. Also, patients in the everolimus arm had worse physical functioning scores.

Dr. Neeraj Agarwal: Yes, Jeanny. In addition to the improved outcomes associated with belzutifan, patient-reported outcomes indicate better disease-specific symptoms and better quality of life among patients treated with belzutifan compared to everolimus. This is great news for patients with advanced renal cell carcinoma. 

Now, Jeanny, can you please tell us about the two abstracts that reported longer follow-up of CheckMate 9ER and CheckMate 214 trials in untreated patients with advanced or metastatic renal cell carcinoma?

Dr. Jeanny Aragon-Ching: Yes, Neeraj. So you are referring to Abstracts 362 and 363. Let's start with Abstract 362. This abstract reports the results after a median follow-up of 55 months in the CheckMate 9ER trial, comparing the combination of nivolumab and cabozantinib to sunitinib in patients with advanced RCC without any prior treatment, so first-line therapy. The primary endpoint was PFS per RECIST 1.1 as assessed by an independent central review. So there were key secondary outcomes including overall survival (OS), objective response rates, and safety. Consistent with prior analysis at a median follow-up time of 18.1 and 44 months, the combination of nivolumab and cabozantinib at a median follow up of 55.6 months continues to show a significant reduction in the risk of progression or death by 42% and in the risk of death by 23% compared to sunitinib. 

Dr. Neeraj Agarwal: And Jeanny, what can you tell us about the efficacy results of this combination by IMDC risk categories?

Dr. Jeanny Aragon-Ching: Similar to prior results in patients with intermediate to poor risk IMDC risk category, the combination treatment maintained significant efficacy and reduced the risk of progression or death by 44% and the risk of death by 27%. To put it simply, the update now shows a 15-month improvement in overall survival with the cabozantinib-nivolumab combination compared to sunitinib, which is amazing. Also, in patients with favorable IMDC risk group, which represented truly a small number of patients in the trial, there was a strong trend for improvement of outcomes as well. I would like to point out that no new safety concerns were identified.

Dr. Neeraj Agarwal: So, it looks like the key message from this abstract is that with longer follow-up, the combination of nivolumab and cabozantinib maintains a meaningful long-term efficacy benefit over sunitinib, supporting its use for newly diagnosed patients with advanced or metastatic renal cell carcinoma.  

Let's move on to Abstract 363, which compares nivolumab with ipilimumab to sunitinib in first-line advanced renal cell carcinoma. What would you like to tell us about this abstract, Jeanny?

Dr. Jeanny Aragon-Ching: Yes, Neeraj. The title of this abstract is "Nivolumab plus Ipilimumab versus Sunitinib for the First-Line Treatment of Advanced RCC: Long-Term Follow-Up Data from the Phase 3 CheckMate 214 Trial." In this abstract, Dr. Tannir and colleagues report outcomes with the longest median follow-up in first-line advanced RCC setting for any clinical trial. So the median follow-up now is about 18 months. The primary endpoints were OS, PFS, and objective response rates, as assessed by an independent review according to RECIST 1.1 criteria in the intermediate to poor risk IMDC risk group, which is the intent-to-treat (ITT) analysis, while secondary outcomes included the same outcomes in the ITT population of patients. Although the progression-free survival was similar in both arms, the combination of nivolumab-ipilimumab reduced the risk of death by 28% compared to sunitinib in the ITT population of patients. When stratifying the results by IMDC risk groups, the combination arm of nivolumab-ipilimumab showed significant improvement in the intermediate to poor risk group, but there was no difference in the favorable risk group. But in the study, no new safety signals were identified.

Dr. Neeraj Agarwal: Thank you, Jeanny, for such a comprehensive description of the results of these two studies. I'd like to add that the median overall survival of patients with metastatic renal cell carcinoma in the ITT population in the CheckMate 214 trial has now reached 53 months, which would have been unimaginable just a decade ago. This is wonderful news for our patients. So the key takeaway from these two abstracts would be that immune checkpoint inhibitor-based combinations remain the backbone of first-line advanced renal cell carcinoma treatment. 

Dr. Jeanny Aragon-Ching: Absolutely, Neeraj. This is wonderful news for all of our patients, especially for those who are being treated for first-line therapy. 

Now, let's move on to the bladder cancer abstracts. We have two exciting abstracts from the UNITE database. What are your insights on Abstract 537, titled "Outcomes in Patients with Advanced Urethral Carcinoma Treated with Enfortumab Vedotin After Switch-Maintenance of Avelumab in the UNITE Study"?

Dr. Neeraj Agarwal: As our listeners know, enfortumab vedotin is an antibody-drug conjugate that binds to a protein called Nectin 4 expressed on bladder cancer cells. In this abstract, Dr. Amanda Nizam and colleagues describe outcomes in 49 patients receiving third-line enfortumab vedotin after prior progression on platinum-based therapy and maintenance avelumab. At a median follow-up of 8.5 months, the median progression-free survival was 7 months and the median overall survival was 13.3 months with enfortumab vedotin in this treatment-refractory setting, the objective response rates were 54%. The message of this study is that enfortumab vedotin is an effective salvage therapy regimen for those patients who have already progressed on earlier lines of therapies, including platinum-based and immunotherapy regimens.

Dr. Jeanny Aragon-Ching: Thank you, Neeraj, for that comprehensive review. 

I want to focus on another patient population in the UNITE database, which is the use of fibroblast growth factor receptor (FGFR) alterations. Can you tell us more about the sequencing now of erdafitinib and enfortumab vedotin in these patients with metastatic urothelial cancer, as discussed in Abstract 616?

Dr. Neeraj Agarwal: Sure, Jeanny. As a reminder, erdafitinib is a fibroblast growth factor receptor kinase inhibitor approved for patients with locally advanced or metastatic urothelial carcinoma harboring FGFR2 or FGFR3 alterations after progression on platinum-based chemotherapy. However, the optimal sequencing of therapies in these patients is unclear, especially with enfortumab vedotin being approved in the salvage therapy setting and now in the frontline therapy setting. 

So in this retrospective study, all patients with metastatic urothelial carcinoma had FGFR2 or FGFR3 alterations. Dr. Cindy Jiang and colleagues report outcomes in 24 patients receiving enfortumab vedotin after erdafitinib, 15 patients receiving erdafitinib after enfortumab vedotin, and 55 patients receiving enfortumab vedotin only. This is a multicenter national study. Interestingly, patients receiving both agents had a longer overall survival in a multivariate analysis, regardless of the treatment sequencing, than patients receiving enfortumab vedotin alone or only with a hazard ratio of 0.52. The objective response rate of enfortumab vedotin in the enfortumab vedotin monotherapy arm was 49%. When these agents were sequenced, the objective response with enfortumab vedotin was 32% after erdafitinib and 67% when used before erdafitinib.

Dr. Jeanny Aragon-Ching: Thank you so much, Neeraj. I think these are important real-world data results, but I would like to point out that larger and prospective studies are still needed to confirm these findings, especially regarding the outcome of erdafitinib after enfortumab vedotin, particularly when the latter is used in the first-line setting.

Dr. Neeraj Agarwal: I totally agree, Jeanny. Now, let's discuss some abstracts related to disparities in the management of patients with genitourinary cancers. 

Dr. Jeanny Aragon-Ching: Sure, actually, I would like to discuss 2 abstracts related to disparities in patients with prostate cancer. So the first one, Abstract 265, titled "Patient-Provider Rurality and Outcomes in Older Men with Prostate Cancer." In this study, Dr. Stabellini, Dr. Guha and the team used a SEER Medicare-linked database that included more than 75,000 patients with prostate cancer. The primary outcome was all-cause mortality, with secondary outcomes included prostate cancer-specific mortality. The investigators showed that the all-cause mortality risk was 44% higher in patients with prostate cancer from rural areas who had a provider from a non-metropolitan area compared to those who were in a metropolitan area and had a provider also from a metropolitan area.

Dr. Neeraj Agarwal: Those are very important data and highlight the healthcare disparities among the rural population with prostate cancer that still exist. 

So what is your key takeaway from Abstract 267, titled "Rural-Urban Disparities in Prostate Cancer Survival," which is a population-based study?

Dr. Jeanny Aragon-Ching: Of course. This abstract discusses, actually, a very similar issue regarding access to healthcare among rural versus urban patients. In this study, Dr. Hu and Hashibe and colleagues and team at the Huntsman Cancer Institute assessed all-cause death and prostate cancer-related death risk in a retrospective study in which patients with prostate cancer based on rural versus urban residencies looked at 18,000 patients diagnosed with prostate cancer between 2004 and 2017. 15% lived in rural counties. Similar to the prior abstract we talked about, patients living in rural areas had about a 19% higher risk of all-cause mortality and a 21% higher risk of prostate cancer-specific mortality in comparison to patients living in urban areas.

Dr. Neeraj Agarwal: So Jeanny, we can say that both of these abstracts, led by different groups of investigators, highlight that patients with prostate cancer living in rural areas have inferior survival outcomes compared to those living in urban areas, and it is time to focus on the disparities experienced by the rural population with prostate cancer. 

Dr. Jeanny Aragon-Ching: Yeah, absolutely Neeraj. I concur with your thoughts. 

So, any final thoughts before we wrap up the podcast today?

Dr. Neeraj Agarwal: Yes, before concluding, Jeanny, I want to express my gratitude for your participation and the valuable insights you have shared today. Your contributions are always appreciated, and I sincerely thank you for taking the time to join us today.  

As we bring this podcast to a close, I would like to highlight the significant advances happening in the treatment of patients with genitourinary cancers during our upcoming 2024 ASCO GU meeting. Many studies featuring practice-impacting data will be presented by investigators from around the globe. I encourage our listeners to not only participate at this event to celebrate these achievements, but to also play a role in disseminating these cutting-edge findings to practitioners worldwide. By doing so, we can collectively maximize the benefit for patients around the world. 

And thank you to our listeners for joining us today. You will find links to the abstracts discussed today in the transcript of this episode. Finally, if you value the insights that you hear on the ASCO Daily News Podcast, please take a moment to rate, review, and subscribe wherever you get your podcasts. Thank you very much. 

Disclaimer:

The purpose of this podcast is to educate and inform. This is not a substitute for professional medical care and is not intended for use in the diagnosis or treatment of individual conditions. Guest speakers express their own opinions, experience, and conclusions. Guest statements on the podcast do not necessarily reflect the opinions of ASCO. The mention of any product, service, organization, activity, or therapy should not be construed as an ASCO endorsement. 

Find out more about today’s speakers:  

 

Dr. Neeraj Agarwal 

@neerajaiims 

Dr. Jeanny Aragon-Ching 

 

Follow ASCO on social media:  

 

@ASCO on Twitter    

ASCO on Facebook    

ASCO on LinkedIn    

 

Disclosures:   

 

Dr. Neeraj Agarwal:    

 

Consulting or Advisory Role: Pfizer, Bristol-Myers Squibb, AstraZeneca, Nektar, Lilly, Bayer, Pharmacyclics, Foundation Medicine, Astellas Pharma, Lilly, Exelixis, AstraZeneca, Pfizer, Merck, Novartis, Eisai, Seattle Genetics, EMD Serono, Janssen Oncology, AVEO, Calithera Biosciences, MEI Pharma, Genentech, Astellas Pharma, Foundation Medicine, and Gilead Sciences   

Research Funding (Institution): Bayer, Bristol-Myers Squibb, Takeda, Pfizer, Exelixis, Amgen, AstraZeneca, Calithera Biosciences, Celldex, Eisai, Genentech, Immunomedics, Janssen, Merck, Lilly, Nektar, ORIC Pharmaceuticals, Crispr Therapeutics, Arvinas  

 

Dr. Jeanny Aragon-Ching: 

 

Honoraria: Bristol-Myers Squibb, EMD Serono, Astellas Scientific and Medical Affairs Inc., Pfizer/EMD Serono 

Consulting or Advisory Role: Algeta/Bayer, Dendreon, AstraZeneca, Janssen Biotech, Sanofi, EMD Serono, MedImmune, Bayer, Merck, Seattle Genetics, Pfizer, Immunomedics, Amgen, AVEO, Pfizer/Myovant, Exelixis,  

Speakers’ Bureau: Astellas Pharma, Janssen-Ortho, Bristol-Myers Squibb, Astellas/Seattle Genetics. 

Drs. Eric Small, Anthony Zietman, and Eric Klein share their reflections as founders of the ASCO Genitourinary Cancers Symposium and discuss key moments in the Meeting’s development, its role in advancing GU cancer research, and major challenges ahead for the field as the Symposium celebrates its 20-year anniversary.

TRANSCRIPT

Dr. Eric Small: Hello, and welcome to the ASCO Daily News Podcast. I'm Dr. Eric Small, your guest host of this ASCO Daily News Podcast today. I'm the co-leader of the UCSF Prostate Cancer Program and deputy director and chief scientific officer at the UCSF Helen Diller Family Comprehensive Cancer Center.

This year, quite amazingly, we're celebrating the 20th anniversary of the ASCO Genitourinary Cancers Symposium, which is hosted annually in San Francisco. The Symposium has heralded some of the biggest strides in GU oncology and has the largest multidisciplinary, global audience for GU cancer research.

I was honored to have a role in the development of ASCO GU two decades ago, along with my friends and colleagues, Dr. Eric Klein, emeritus professor and chair of the Glickman Urological and Kidney Institute at the Cleveland Clinic. And Dr. Anthony Zietman, a professor of radiation oncology at Harvard Medical School and the Massachusetts General Hospital.

On today's episode, we'll be reflecting on key moments in the meeting's development, its role in advancing GU cancers and GU cancer research, and major challenges that lay ahead for the field. You'll find our full disclosures in the transcript of this episode, and disclosures of all guests on the podcast are available at asco.org/DNpod.

Eric and Anthony, I'm delighted to have this opportunity to catch up with you both to discuss ASCO GU, thank you for coming on the podcast today.

Dr. Eric Klein: Thanks for having us.

Dr. Anthony Zietman: Thanks for the invitation.

Dr. Eric Small: Well, it's really exciting and it's wonderful to see the two of you. So, the ASCO GU Symposium has been a key annual event for all of us in the GU field. But to give our listeners some background, when the Symposium was first created, when we first met in San Francisco, starting on Thursday, February 17, 2005, it brought together 1,035 individuals interested in the prevention and treatment at that point of prostate cancer alone.

At that time, the meeting was co-sponsored by ASCO, the American Society for Therapeutic Radiology and Oncology or ASTRO, the Society of Urologic Oncology (SUO), and the Prostate Cancer Foundation. It was actually the culmination of several years of planning. Clearly, it represented the first truly multidisciplinary scientific and educational meeting dedicated solely to prostate cancer, and we'll come back to talk about that.

The meeting went back and forth between San Francisco and Florida for a few years before finally, settling permanently in San Francisco. In the last 20 years, ASCO and the Symposium's co-sponsors expanded the meeting to include all genitourinary specialties. This year, ASCO received more than 875 abstract submissions and anticipates that there will be even more attendees than last year.

On a personal note, it's truly amazing to me that here we are, 20 years later, and the meeting is going stronger than we could ever have imagined. I must say that my motivation to help organize this meeting stem from two issues that were somewhat in tension with each other.

First, the field of prostate cancer and prostate cancer research was just starting to take off at the time, and we really needed, as a community, a venue where across disciplines, we could talk and meet with each other. But that was in real tension, at least at ASCO, where we were relegated at the Annual Meeting to a tiny room at the far end of the convention center on the last day of ASCO, because really, that's all we could muster.

And I do remember making a pitch, assuring folks that there was an unmet need, and that the field was going to take off, who knew? So, I'm wondering, and either of you can jump in (Dr. Klein, Dr. Zietman), tell us how you got involved in the first GU meeting, and what's the most salient feature of your involvement? Anthony, do you want to start?

Dr. Anthony Zietman: I think it's really important to discuss the historical context at which this meeting was born. Back in the 1990s, we were incredibly polarized as specialties in GU oncology. PSA had been introduced in the late '80s, early '90s, screening was everywhere. There was a tidal wave of patients and an almost reckless race to treatment.

All surgeons believed that all patients with localized early prostate cancer needed surgery and that they could do individually, a beautiful job. And all radiation oncologists believed that they could deliver morbidity-free treatment and could do it to everyone regardless of your age or stage.

And there were a few, there were a few who thought maybe we didn't need to screen everyone, and maybe there was a little bit of overtreatment, maybe we've gone a little bit too far, but those voices were really suppressed in the '90s. Those voices didn't have a voice.

Many of us also believed there was more morbidity to our treatment than we'd appreciated. And that was the media in which, us three, all young research physicians, probably all in our low forties were given the charge of this meeting. And the thing I most remember about it in the planning, is that we actually decided collectively to give voice to everyone, including maverick voices.

It wasn't just about the party line, and it wasn't just about the North American line, there were Britts and there were Swedes, and there were Dutchmen who had very important things to say as well, and very, very different perspectives. And we also chose to give voice to young people as well as just our party elders, so to speak.

I don't know which of us, if any of us, or maybe it was our society suggested but we do it all in a single room such that rad oncs and surgeons were all together, and it led to a kind of forced truthfulness, which started to break down this groupthink that we developed in our own silo.

So, when I look back, I think that that context was very important and that what we sought as young program chairs was we sort of tapped in something that was latent in our field. Eric KIein, I don't know if you remember things as I did.

Dr. Eric Klein: I do. And things were very siloed then. We had hired early in the mid-90s, I think, a young radiation oncologist named Pat Kupelian, who became a close collaborator and a good friend, and who really changed the narrative around treating prostate cancer at the Cleveland Clinic, which was all surgical prior to that time. And he did such high-quality work, it was hard not to pay attention. And he actually took it on himself in his early years when he wasn't very busy to sit down and go through all the patients that we had treated with prostate cancer at the Cleveland Clinic, radiation versus surgery, and had the temerity to write a manuscript that showed that there was no difference in survival, based on PSA biochemical recurrence and metastasis and that sort of thing.

And that was sort of game changing. And it really clued me into the fact that for patient's sake, we needed to be talking to our colleagues. The second perspective was from the perspective of having attended a couple of Prostate Cancer Foundation meetings. And I think they really deserve credit for increasing the visibility of prostate cancer research, and funding it and recruiting really good scientists from other disciplines.

When young scientists were told, and we heard this repeatedly, "Don't spend your career researching prostate cancer, it's a dead end." And PCF did a great job of having a multidisciplinary meeting, which was smaller and not so clinically focused, but also got me excited.

Dr. Eric Small: I think you're right, Eric. And I think that the transdisciplinary nature, as Anthony pointed out was new, it was innovative. No one had really, really thought about it. It was at the margins in different meetings. Your comments about PCF, Prostate Cancer Foundation, resonate because we did take a page from their book in many ways although that meeting, as you point out, is much more basic research-focused.

I don't know if you guys recall that first year, in fact, PCF was a co-sponsor. We actually had asked Mike Milken to give a talk and he did. And obviously, once we expanded to the broader GU cancers, it was less pertinent for PCF to be involved. But absolutely, I agree with you, Eric, they deserve credit.

PCF, and the PCF involvement, was one of the things that changed. There's many things that are constant that haven't changed, even though the science clearly has evolved dramatically. And I'm wondering if you guys can comment on things that are the same.

One thing that stands out for me: I had the opportunity to look through the agenda for the 2005 meeting. And right there, very prominently, was a special lunch session that we had designed for mentorship and career development for trainees and early career investigators, and that's still ongoing and others have modeled it. And I think that was one amazing feature of this.

One of you, I think Anthony mentioned that we invited a lot of young people to speak and to be the path blazers, but we also did this career development piece, and it was a wonderful event. I wonder if either of you or both of you could comment on other things that you think are constants and you anticipate will always be there.

Dr. Anthony Zietman: I think to me that constant is that every time I go, I hear speakers I've not heard before. Often very senior speakers, I've never heard them before. But it is the practice of GU ASCO to invite people that are outside your sphere of experience, which is very challenging.

Dr. Eric Klein: Two things strike me. I think one is the international nature of the faculty. We tried very hard (and subsequent program directors have) to be very inclusive and to bring the work that was the most cutting-edge to the stage. There are lots of things that are done in Europe that started there sooner. PSMA treatment, for example, and many other ProtecT trial and many other things.

And the debates on stage and how that gave the opportunity for every subspecialty to have the opportunity to share its perspective on particular case management issues and case management conferences, I think have been around forever. And maybe, the most valuable part of it all is to hear people's perspective on how to manage a particular patient.

Dr. Eric Small: I think the other comment you made Anthony that resonated and still goes on, was it was a conscious decision to have a single session in one room where everyone attended. And not to do the usual small breakouts and concurrent sessions, but sort of the philosophy being, is we all need to hear the same thing, we all need to be in the same room at the same time. And it really fostered this transdisciplinary approach; it was truly educational for us. Now, it's sort of part of what we do, and part of what our patients expect of us. I think that bringing us all together into one room was really great.

Dr. Anthony Zietman: But it's now so part of what we do, but it's difficult certainly for younger faculty and for residents to believe we ever did it any other way. But we did, and I don't know whether ASCO GU led that or reflected that, but that was the zeitgeist among young individuals like us. And it's really become the culture of contemporary practice.

Dr. Eric Small: So, given that that's the culture now, which it is, and I think sure, we should take credit for it, at least in GU: why then is it important for people to continue to attend GU ASCO today if it's now our culture to do that?

Dr. Anthony Zietman: For me, it's because we share information as equal partners in a multidisciplinary team. And our practice is so multidisciplinary and multi-modality these days that we can't exist alone, we no longer try to.

Dr. Eric Klein: Nor can we. The amount of knowledge that's being generated in each subspecialty and it's spinoffs is so great. It's impossible for a busy surgeon to stay on top of that. And this is sort of one-stop shopping for everything that's really current and appropriate to know about.

And again, I always look at these things from the patient perspective, and my ability to counsel patients about what their best treatment options might be, I thought more and more dependent, and I think today more and more depends on being knowledgeable about everything that's going on, and not just one narrow field that you happen to be an expert in. And that's why I think it's so important for youngsters to attend and even oldsters like us to attend to stay current.

Dr. Anthony Zietman: Yeah, and also, multidisciplinary means so much more these days. It does mean oncologists and radiologists, information technologists. I mean, who knows what it'll mean in the future, but it's always expanding.

Dr. Eric Small: And I think it's interesting, back when we did this, when we started it, we were worried about being able to fill one meeting with prostate cancer information - we did easily. It was not immediately clear that there was a role or room for additional GU cancers. And then there was an explosion both in kidney cancer work at first, and then bladder cancer. And now it's unbelievable how much is there. And perhaps, this meeting needs to be twice as long.

So, I agree with you guys. I think that it's the best way to stay current. The other thing that I really appreciate about this meeting and others have a hard time doing it, is that it provides, as Eric indicated, for the busy clinician. It integrates sort of the important information that's coming in terms of more basic science and makes it readily available and digestible, which isn't always the case at pure science meetings and may or may not be apparent in other meetings.

I, again, was looking at the preliminary agenda in 2005, we had asked Bill Nelson to talk about molecular targets or prevention, how forward-thinking. And that's continued to be the case that this is a meeting where you get that integration from the laboratory.

Dr. Anthony Zietman: Well, and I would add to that, not just the integration of it, it's where now you get to hear things first. I mean, it used to be that, you went the AUA or ASTRO or ASCO to hear things. Now, everyone one wants to present it first at GU ASCO.

Dr. Eric Klein: Yes, that's correct.

Dr. Anthony Zietman: And I think we actually made it permissible in the early days that you could present at GU ASCO and at your specialty meeting.

Dr. Eric Small: What are the challenges in the field that are going to likely shape the content of future meetings? And we've all alluded to the fact that the meeting is evolving and has done a really good job of staying current with the clinical science. But beyond that, what do you two feel are important areas that this meeting is likely to continue to address?

Dr. Eric Klein: So, biomarker development has always been an important part of this meeting, and I think we need to broaden our view of what biomarkers are now, and in the AI era, digital pathology and AI-based models that predict treatment response and outcome. My hope is that they will be studied in a rigorous fashion, and that they will end up outperforming the kind of single biomarker approach that we've used in the past.

And we need to understand that; we need to understand the science behind AI to a certain level, and we need to understand what questions AI can address, and how that might be useful. But I'm particularly excited about digital pathology where sampling error becomes less of an issue and the number of potential inputs you're looking at that are related to the output should increase exponentially.

Dr. Anthony Zietman: And I would add on the AI side of things, as a former journal editor, when AI papers came into the journal, we actually didn't have enough people who could review them, who had the understanding to review these papers and tell us, "Is this a good paper or a bad paper?"

So, we're going to need to increase our understanding of AI, Eric, as you said. So, I think that will be a push in the years to come. Also, on a very practical level, it is such a popular meeting, keeping us all under one roof and in one room, will become just difficult. But it's part of the culture of the meeting, and I think it's what people want.

Dr. Eric Small: It's a good challenge to have.

Dr. Eric Klein: Feeding everybody too. I recall one constant has always been really good breakfasts and lunches.

Dr. Eric Small: Right, that has been a standard of ours. One of the interesting things that I think has changed, we saw glimmers of it back in 2005, but it was early on and it was, I think very early on in sort of a good understanding of social determinants of health and equitable access to healthcare and the challenges posed by incredible technology development and making sure that that doesn't increase disparities. And I think that that focus has increasingly been present in meetings and is not going to be lost. And it also speaks, one of you spoke to our international audience, that increasingly, I think this meeting is going to address urologic oncology and how we address it not only in developed countries, but in lower- and middle-income countries. And I think that will be a focus as well.

I'm excited with what the future holds for ASCO GU. It has been an incredible run. I'm hoping that we'll be able to perhaps catalog some of the salient presentations that have been done at this meeting over the years, but there's no question as both of you have pointed out, this has become the venue.

Well, thank you both for sharing your insights with us today on the ASCO Daily News Podcast. Really wonderful to see you both and talk with you.

Dr. Eric Klein: Great to be here. Thanks.

Dr. Anthony Zietman: Great to be here. Looking forward to the next 20 years.

Dr. Eric Small: That's right.

Dr. Anthony Zietman: If I'm still around.

Dr. Eric Klein: Yeah, let's do this again in 20 years. That'd be great.

Dr. Eric Small: We will. And thank you to our listeners for your time today. If you value the insights that you hear on the ASCO Daily News Podcast, please take a moment to rate, review and subscribe wherever you get your podcasts. Thank you.

Disclaimer:

The purpose of this podcast is to educate and to inform. This is not a substitute for professional medical care and is not intended for use and the diagnosis or treatment of individual conditions. Guests on this podcast express their own opinions, experience, and conclusions. Guest statements on the podcast do not express the opinions of ASCO. The mention of any product, service, organization, activity, or therapy should not be construed as an ASCO endorsement.

Follow today’s speakers:  

Dr. Eric Small

Dr. Eric Klein

@EricKleinMD

Dr. Anthony Zietman

 

Follow ASCO on social media:   

@ASCO on Twitter   

ASCO on Facebook   

ASCO on LinkedIn   

 

Disclosures:  

 

Dr. Eric Small:

Stock and Other Ownership Interests: Fortis, Harpoon Therapeutics, Teon Therapeutics

Honoraria: Janssen

Consulting or Advisory Role: Janssen Oncology, Teon Therapeutics, Fortis

 

Dr. Anthony Zietman:

Leadership: Elsevier

 

Dr. Eric Klein:No relationships to disclose

Drs. John Sweetenham and Fred Locke discuss the FDA investigation on the risk of cancer from CAR T-cell therapy and share insights on the known number of cases and the potential implications on clinical research and patient care.

TRANSCRIPT

Dr. John Sweetenham: Hello, I’m Dr. John Sweetenham from the UT Southwestern Harold C. Simmons Comprehensive Cancer Center and host of the ASCO Daily News Podcast. CAR T-cell therapies have been game changers for treating certain cancers including lymphomas and leukemias, as well as multiple myeloma, since the vast majority of patients who have received CAR-T do not have other curative options with conventional non-cellular, anti-cancer therapies.

But on November 28, the U.S. Food and Drug Administration announced that it is investigating whether CAR T-cell therapy can, in rare cases, cause secondary cancers. The FDA launched the probe after receiving reports from clinical trials and other data sources of T-cell malignancies in patients who received CAR T-cell immunotherapies.

Joining me to discuss the investigation and its implications for the field is Dr. Fred Locke, a medical oncologist and translational researcher and a senior member and chair in the Department of Blood and Marrow Transplant and Cellular Immunotherapy at the Moffitt Cancer Center in Tampa, Florida.

Dr. Locke is an internationally renowned clinical research leader in the field of CAR T-cell therapy. You'll find our disclosures in the transcript of this episode, and disclosures of all guests on podcasts are available at asco.org/DNpod.

Fred, it’s great to have you on the podcast today.

Dr. Fred Locke: Thanks, John, I’m really glad to be here.

Dr. John Sweetenham: So, T-cells are the backbone of CAR T-cell therapies, and there are currently 6 CAR-T products approved by the FDA. As our listeners will know, CAR T-cell therapies manipulate a patient's T-cells, enabling them to recognize and attack antigens on cancer cells and induce potential long-standing changes in the immune system.

In its statement on November 28, the FDA said it determined that the risk of T-cell malignancies is applicable to all of the currently approved BCMA- and CD19-directed, genetically modified, autologous CAR T-cell immunotherapies. Fred, could you comment for us on the investigation: How many patients are reported to have developed second malignancies from CAR T-cell therapy, and whether there are likely to be more secondary cancers reported?

Dr. Fred Locke: Yes, so the FDA and the reports are coming out that there are 19 cases of T-cell malignancy that we're aware of that have occurred after the current FDA-approved CAR T-cell therapies were administered for the treatment of leukemia, lymphoma, or multiple myeloma. The majority of those cases were reported through the FDA Adverse Event Reporting System. And we don't know a lot of details of those 19 cases.

We think that there's probably about 13,000 to 14,000 patients who've been treated with the commercial CAR T-cell therapies. So if you kind of do some crude math, you can come up with 19 out of say, 13,500; we're at about 0.1% of patients who could have developed T-cell lymphoma after treatment with these CAR T-cell therapies. It's not entirely out of the realm of possibility that T-cell lymphoma could develop from gene-modified T-cells, and these are all the patient's own T-cells that have been modified outside of the body. But I would still posit that this is a really low incidence of T-cell lymphomas in these patients who really are without other great treatment options.

Dr. John Sweetenham: Yeah, and I think that's a point that we'll return to a little bit later on in the conversation around the fact that you know, clearly, there are major benefits that have been associated with CAR T-cell therapy and hematologic malignancies so far. And of course over the years, I think that many of us have become familiar with and learned a great deal about how to manage some of the more serious side effects of CAR T-cell therapy. And you, of course, have led several pivotal national trials of anti-CD19 CAR-Ts for lymphoma.

Can you comment at all on whether you've seen previous data from your own practice or others on the risk of second malignancy from CAR T-cell therapy? And can you share your insights on the data and any new emerging data that warrants our attention for the concern or risk of second malignancy? And I guess to round up that series of questions, is there anything currently in yours or others research into CAR-T to explain what's happening and why this is going on?

Dr. Fred Locke: I think what may have prompted the FDA’s announcement of this is that on the same date that they came out with announcing their investigation, there was the release of the abstracts for the American Society of Hematology Annual Meeting. And within those abstracts, and unfortunately it was not selected for poster or oral abstract presentation, but discovered within those abstracts was one on a CAR+ T-cell lymphoma after ciltacabtagene autoleucel therapy for relapsed refractory multiple myeloma.

And what these investigators and the company were reporting is that a patient with refractory multiple myeloma received the cilta-cel BCMA-directed CAR T-cell therapy and developed a stringent complete response, and about 5 months later developed a nasal facial plaque and PET+ cervical lymph nodes. And both the lymph nodes and the plaque were biopsied and showed a T-cell lymphoma in which 90% to 100% of the cells were positive by qPCR for the CAR construct and immunohistochemistry for the CAR protein. So this was a T-cell lymphoma growth where the cells were expressing the inserted protein, the chimeric antigen receptor protein, which is obviously not natural.

And when they looked a little bit deeper at these patients, 91% of the cells have the same T-cell receptor sequence. So this was really a clonal sort of process. They did CAR integration analysis to see how the insertion of the CAR, the chimeric antigen receptor gene, could have potentially disrupted a gene within the T-cells. And what they found is that there were some dominant sort of insertions within certain genes suggesting monoclonality, but it wasn't within any sort of obvious activating genes that would be expected to lead to the T-cell lymphoma.

They went on and did some additional analysis, and they showed that there was some existing TET2 mutations in the T-cells of this patient, prior to probably prior to the CAR T-cell manufacturer, and they weren't associated with clonal insertion. And I think, you know, it's possible that this patient who had a pre-existing mutation may have been susceptible to the development of a T-cell lymphoma prior to the CAR T-cell treatment. And TET2 was previously shown a number of years ago in a CLL patient treated with CD19 CAR T-cell therapy; it was shown that there was insertional mutagenesis, silencing the TET2 gene, and that associated with clonal expansion of the CAR T-cells in that patient and corresponded with remission of the CLL. However, the difference here is that that patient's T-cell clone went back down and contracted, and the patient remained in remission 5 years later with their T-cells still in the blood, but the minority of those T-cells had that that TET2 mutational insertional mutagenesis.

All this is something we thought was theoretically possible, that T-cell lymphoma could develop after car T-cell therapy. And in fact, a prior trial using a different method of delivery of a CAR gene; instead of using a virus to insert the car into the into the T-cells, a transposon system called piggyBac was used. And in that trial, again, CD19 CAR trial, but in this case, it was allogeneic donor cells for patients who had relapsed after an allogeneic transplant. So it's sort of an autologous, you know, analogy, but it's using the donor cells. And in that trial, 2 out of like 10 patients developed clonal T-cell lymphoma, which was CAR+, but they weren't able to identify a clear insertional mutagenesis event in those cases. So, we've known this is possible, and it would have been great if this poster or if this abstract at ASH was presented as an oral or a poster so we could get more detail, but it's possible that that's the likely reason for the FDA’s announcement.

Dr. John Sweetenham: Thanks. The bottom line, I guess, is that for now, the jury's still out on exactly what's underlying these observations, but something which I'm sure is going to be the subject of a lot of discussion during the ASH meeting this year and moving forward.

I'd like to inform our listeners that ASCO released a statement on the FDA investigation, stating that the risk of T-cell malignancies due to CAR T-cell therapy appears to be very low. And we've just heard from Dr. Locke that, of the several thousand patients who've received CAR Ts, there are 19 cases so far, it's been reported, which puts us into some type of proportion.

The ASCO statement goes on to say that based on available data, and while such malignancies have occurred in patients who have received CAR T-cell therapy, the causal relationship, whether these cases are spontaneous or are caused by the therapy, needs to be investigated further, and we've just heard a little about the detail of that.

ASCO added that by issuing a warning but not revoking approval of these therapies, the FDA clearly believes that the current available evidence suggests the overall benefits of these products, used within their approved label, continue to outweigh the potential risks.

So Fred, the risk of secondary malignancies is already included as a class warning in the U.S. prescribing information for these CAR T-cell therapies. But do you think that the CAR-T products could eventually be taken off the market, and how would your research be impacted if this were to happen? And maybe finally, how long will patients on CAR T-cell therapy need to be monitored moving forward?

Dr. Fred Locke: I don't believe that CAR T-cell therapy will be taken off the market. As we've already talked about, the incidence is extraordinarily low and the causality is unclear. It would certainly impact my research, as I'm doing clinical trials with CAR T-cell therapies, but it would more importantly impact the way we treat patients. We did over 300 CAR T-cell therapy treatments last year here at Moffitt Cancer Center. We're one of the busiest programs in the world giving CAR T-cell therapy, and it is truly a transformative therapy for all the diseases that we administer these FDA-approved therapies for. For example, in diffuse large B-cell lymphoma, we participated in the ZUMA-7 clinical trial and recently reported that patients randomized to CAR T-cell therapy had improved overall survival. They were living longer than patients randomized in the second-line setting to get conventional chemotherapy and autologous transplant.

This is clearly a therapy that can work. I would also add that the risk of secondary malignancies is real, but that's a risk for all cancer patients, particularly patients with hematologic malignancies, and for example, lymphoma patients who've gotten an autologous stem cell transplant are at a relatively high lifetime risk of developing a secondary myeloid malignancy, most commonly, treatment-related MDS or AML. And that risk is also present after CAR T-cell therapy. The degree of attribution of CAR-T versus the condition of chemotherapy for CAR-T versus the previous chemotherapy is all unclear, and more analysis needs to be done. But the risk of developing treatment-related MDS or leukemia is certainly higher than the small number of T-cell lymphomas reported.

The other thing I want to point out is that there was an analysis of the SEER database that patients with B-cell lymphomas are at about a 5-fold higher risk of developing a T-cell lymphoma than the otherwise healthy population; and vice versa, by the way, T-cell lymphoma patients are at risk for developing B cell lymphoma. And in fact, in that SEER database, it's not a wildly different percentage chance of developing a T-cell lymphoma after a B-cell lymphoma. And this data came out before the advent of CAR T-cell therapy. So I really think we need more science to be done to understand what's happening for these patients.

Will this impact the field? Well, certainly, there are treatments that are not CAR T-cell therapy that compete with CAR T-cell therapy or could; I'm a strong believer that they don't offer the same outcomes for patients, but we will certainly see people talking about this for some time. Then the other place where this could be relevant, I think, is as we look at CAR T-cell therapy for autoimmune disorders, and we're starting to see studies of that for lupus and other diseases, the risk to benefit ratio could be different in those cases. So this is something we really need to consider as we move forward with CAR T- cell therapy.

Dr. John Sweetenham: Yeah, thanks, Fred. And as a major clinical investigator in the field of CAR-T at the moment, do you see any potential concerns about difficulties in getting patients onto the trials of CAR T-cell in the light of this information?

Dr. Fred Locke: No, I really don't. We're not seeing hesitancy, at least in the patients who are referred in for CAR T-cell therapy. Again, it may give ammunition for those who are already predisposed to not refer patients in for CAR T-cell therapy, but I don't think it should. I think that these are low risks, and these therapies clearly have benefits to patients. And we should give their patients an opportunity to get these therapies, and I don't see it impacting our clinical trials at this point.

Dr. John Sweetenham: Yeah, and your comments address what was going to be my final question to you and that is, as a referring oncologist, how would you advise a referring oncologist to talk with their patients about these data and their implications moving forward?

Dr. Fred Locke: If the patient brings it up, I think the response should be that these are very few cases of very low incidence and very low risk. There are other risks to CAR T-cell therapy that are greater, and really speaking with a cell therapist who administers the treatment is probably the best way to give the patient the option to get CAR T-cell therapy if they want to, knowing all the risks and benefits. So, I would leave it up to the CAR-T treatment center to discuss those risks with the patient.

 

Dr. John Sweetenham: Well, thanks, Fred, for sharing your insights with us on these concerning developments in CAR T-cell therapy, and I think also for putting them into context in terms of the sort of magnitude of this problem in the context of the overall number of patients who are benefiting from this therapy right now. We truly appreciate your time, and thanks for sharing your thoughts with our listeners.

Dr. Fred Locke: Thanks, John, my pleasure.

Dr. John Sweetenham: And thank you to our listeners for your time today. If you value the insights you hear on ASCO Daily News Podcast, please take a moment to rate, review, and subscribe wherever you get your podcasts.

Disclaimer: 

The purpose of this podcast is to educate and to inform. This is not a substitute for professional medical care and is not intended for use in the diagnosis or treatment of individual conditions. Guests on this podcast express their own opinions, experience, and conclusions. Guest statements on the podcast do not express the opinions of ASCO. The mention of any product, service, organization, activity or therapy should not be construed as an ASCO endorsement. 

 

Find out more about today’s speakers:   

 

Dr. John Sweetenham

Dr. Fred Locke

@DrFredLocke

   

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Disclosures:   

   

Dr. John Sweetenham:   

Consulting or Advisory Role: EMA Wellness  

 

Dr. Fred Locke:

Consulting or Advisory Role: Novartis, Celgene, Calibr, Allogene, Gerson Lehrman Group, EcoR1, Amgen, Bluebird Bio, Bristol Myers Squibb, Iovance Biotherapeutics, Legend Biotech, Cowen, Kite (Gilean), Umoja Biopharma, Takeda, Sana Biotechnology, Daiichi Sankyo/UCB Japan, Bristol-Myers Squibb/Celgene, Janssen, A2 Biotherapeutics, Mittenyi Biotec, Caribou Biosciences, Takeda, Umoja Biopharma

Research Funding: Kite Pharma, Allogene, Novartis, Bluebird Bio, Bristol-Myers Squibb/Calgene

Patients, Royalties, Other Intellectual Property: Double Mutant Survivin Vaccine. US010414810B2

CAR T Cells with Enhanced Metabolic Fitness; Serial Number: 62/939,727

Methods of Enhancing CAR T Cell Therapies. Serial Number: 62/892,292.

Evolutionary Dynamics of Non-Hodgkin Lymphoma CAR-T cell therapy.  Serial Number: 62/879,534.

Travel, Accommodations, Expenses: Kite Pharma, A2 Biotherapeutics