ASCO Daily News

Dr. Allison Zibelli and Dr. Megan Kruse discuss key research on breast cancer, including potential benefits of endocrine therapy in ER-low breast cancer, triplet therapy in PIK3CA-mutated, HER2-negative cancer, and abstract 505 on chemotherapy benefit in premenopausal women with intermediate risk oncotype scores. They also touch on using anti-mullerian hormone levels to predict chemotherapy benefit and exploring new combination trials for relapsed breast cancer patients.

Dr. Vamsi Velcheti, along with Dr. Sandip Patel and Dr. Michael Zervos, explores the optimization of neoadjuvant and adjuvant treatment options for early-stage NSCLC patients. They discuss the evolving role of surgery in the era of targeted therapy and immuno-oncology in lung cancer, emphasizing the importance of multidisciplinary collaboration and proper patient selection for optimal care.

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 Follow ASCO on social media: @ASCO on Twitter ASCO on Facebook ASCO on LinkedIn 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

Experts Drs. Shaalan Beg and Aparna Parikh discuss the role of ctDNA in GI cancers, its impact on risk stratification and recurrence detection. They highlight studies like COBRA and GALAXY in CRC, emphasizing ctDNA's potential in preoperative iCCA detection.

Drs. Shaalan Beg and Travis Osterman discuss a new machine learning model that uses electronic health record data to predict immune checkpoint inhibitor effectiveness and toxicity. The AI model can personalize risk-benefit profiles, inform treatment decisions, and enhance clinical trial selection. They delve into the significance of accurately identifying patients who benefit from treatment while avoiding adverse reactions.

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. Find out more about today's guest: Dr. Shaji Kumar @myelomaMD Follow ASCO on social media: @ASCO on Twitter ASCO on Facebook ASCO on LinkedIn Disclosures: 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 Follow ASCO on social media: @ASCO on Twitter ASCO on Facebook ASCO on LinkedIn 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 at the 2024 ASCO Gastrointestinal Cancers Symposium, including advancements in precision oncology for esophageal squamous cell carcinoma, hepatocellular carcinoma, and colorectal cancer. They explore innovative approaches in personalized care, immunotherapy options, FGFR inhibitors, and the importance of genomics in predicting outcomes for colorectal cancer patients.

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. Find out more about today's speakers: Dr. Neeraj Agarwal @neerajaiims Dr. Todd Morgan @wandering_gu 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. 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

Neeraj Agarwal, an oncology specialist, and Jeanny Aragon-Ching discuss key abstracts at the GU Cancers Symposium, including combo therapies for mCRPC, updates on trials in ccRCC, and a retrospective study in mUC. They also touch on treatment outcomes in bladder cancer and disparities in prostate cancer patients.