ASCO24: The Future of Personalized Immunotherapy

Dr. Diwakar Davar and Dr. Jason Luke discuss key abstracts from the 2024 ASCO Annual Meeting that explore triplet therapy in advanced melanoma, TIL cell therapy in immune checkpoint inhibitor–naive patients, and other novel approaches that could shape the future of immunotherapy in melanoma and beyond.  TRANSCRIPT Dr. Diwakar Davar: Hello and welcome to the ASCO Daily News Podcast. I am your guest host, Dr. Diwakar Davar. I'm an associate professor of medicine and the clinical director of the Melanoma and Skin Cancer Program at the University of Pittsburgh's Hillman Cancer Center. I'm delighted to have my friend and colleague, Dr. Jason Luke, on the podcast today to discuss key abstracts in melanoma and immunotherapy that will be featured and highlighted at the 2024 ASCO Annual Meeting. Dr. Luke is an associate professor of medicine, the director of the Cancer Immunotherapeutic Center, as well as the associate director for clinical research at the University of Pittsburgh's Hillman Cancer Center.  You will find our full disclosures in the transcript of this episode.  Jason, as always, it's a pleasure to have you on this podcast to hear your key insights on trials in the immunotherapy space and melanoma development paradigm, and to have you back on this podcast to highlight some of this work.  Dr. Jason Luke: Thanks so much for the opportunity to participate. I always enjoy this heading into ASCO.  Dr. Diwakar Davar: We're going to go ahead and talk about three abstracts in the melanoma space, and we will be starting with Abstract 9504. Abstract 9504 essentially is the RELATIVITY-048 study. It describes the efficacy and safety of the triplet nivolumab, relatlimab, and ipilimumab regimen in advanced PD-1 naive melanoma. So in this abstract highlighted by Dr. Ascierto and colleagues, they report on the results of this phase 2 trial in this setting. By way of background, PD-1 inhibitors and immune checkpoint inhibitors starting in PD-1 and CTLA-4, as well as PD-1 and LAG-3, are all FDA-approved on the basis of several pivotal phase 3 trials, including KEYNOTE-006, CheckMate-066, CheckMate-067, and most recently, RELATIVITY-047. Jason, can you briefly summarize for this audience what we know about each of these drugs, at least the two combinations that we have at this time?  Dr. Jason Luke: For sure. And of course, these anti PD-1 agents, became a backbone in oncology and in melanoma dating back to more than 10 years ago now, that response rates in the treatment-naive setting to anti PD-1 with either pembrolizumab or nivolumab are roughly in the range of mid-30s to high-40s. And we've seen clinical trials adding on second agents. You alluded to them with the seminal study being CheckMate-067, where we combined a PD-1 antibody and CTLA-4 antibody or nivo + ipi. And there the response rate was increased to approximately 56%. And more recently, we have data combining PD-1 inhibitors with anti-LAG-3. So that's nivolumab and relatlimab. Now, in that trial, RELATIVITY-047, the overall response rate was described as 43%. And so that sounds, on a first pass, like a lower number, of course, than what we heard for nivolumab and ipilimumab. We have to be cautious, however, that the cross-trial comparison between those studies is somewhat fraught due to different patient populations and different study design. So I think most of us think that the response rate or the long-term outcomes between PD-1, CTLA-4, and PD-1 LAG-3 are probably roughly similar, albeit that, of course, we have much better or much longer follow up for the nivo + ipi combo.  The one other caveat to this, of course then, is that the side effect profile of these two combinations is distinct, where the incidence of high-grade immune-related adverse events is going to be roughly half with nivolumab and relatlimab, a combination of what you would see with the nivolumab and ipilimumab. So that has caused a lot of us to try to think about where we would use these different combinations. But we do see that all of these treatments can land a durable long-term response in the subset of patients that do have an initial treatment benefit. The landmark, I think, for the field has been the 7-and-a-half-year median overall survival that we've seen with PD-1 plus CTLA-4, nivo + ipi; of course, we don't have such long-term follow up for PD-1 and LAG-3. But I think that's the setting for thinking about the rationale for combining a triplet regimen of PD-1, CTLA-4, and LAG-3. Dr. Diwakar Davar: So, Jason, in your mind, given the difference in the disparity and durability of the responses for the 067 regimen of nivo-ipi, and the RELATIVITY-047 regiment of nivo-rela, what is the standard of care in the U.S., and how does it change in the rest of the world, knowing that nivo-rela is not necessarily approved in all jurisdictions? Dr. Jason Luke: So this is a major complication in our field, is that there is perhaps not complete agreement across the world in terms of what the frontline standard of care should be. I think most United States investigators, or those of us that really treat melanoma most of the time, would suggest that a combination regimen, given the enhanced response rate and longer-term outcomes, should be the consideration for the majority of patients. In fact, in my practice, it's hard to think of who I would treat with a monotherapy PD-1 approach in the PD-1 naive setting. So either nivo + ipi or nivo + rela. As you alluded to however, in other regulatory settings throughout the world, combinations might not actually even be approved at this point. So PD-1 monotherapy would be the backbone of that setting. It does set up some complications when you think about a comparator arm; say you were going to look at various combinations, probably PD-1 monotherapy would be the worldwide comparator. You have to understand though, in the United States, I think that that's a less attractive option. Dr. Diwakar Davar: So in RELATIVITY-047, Dr. Ascierto and his colleagues are looking at generating a triplet. And in this case, they looked at this in the context of frontline metastatic melanoma, 46 patients. Very interestingly, the dose of ipilimumab studied here was 1 mg/kg through 8 weeks, not the 3 mg/kg every three weeks times four doses using 067, or even the low dose ipilimumab regimen that you studied in the second line setting, which was 1 mg/kg every 3 weeks for 4 doses. So let's talk about the results and specifically the implications of potentially studying lower doses of ipi. Dr. Jason Luke: I appreciate you raising that point. I think it's really important as we think about this dataset because this triplet regimen is not by any means the only version of a triplet that could be developed using these agents. So just to give the high-level numbers from the abstract, we see from these data that the overall response rate is described as 59% and 78%, a disease control rate with patients having an unreached link. So duration of response of unreached, and then the progression-free survival at about 5 months. So those are really interesting data. But as was alluded to, it's not totally clear to me that that's the best that we could do with this regimen.   Now, you alluded to this low-dose ipilimumab schedule at 1 mg/kg every 8 weeks, and it's really important to note that we have no benchmark for that regimen in melanoma oncology. And in fact, the one study that used that regimen, which was the adjuvant study of nivolumab and ipilimumab, known as CheckMate915, is in fact the only immune checkpoint inhibitor study in melanoma oncology that was actually negative. That study noted no benefit to adding ipilimumab at 1 mg/kg every 8 weeks on top of nivolumab, again, the adjuvant setting. So it's a little bit curious to then understand what it means in this study to have that amount of ipilimumab added to the rela-nivo backbone. And that manifests in a few different ways. We see the response rate here at 59%. Again, if you compare that just against the standard nivo + ipi dosing schedule, it's about the same. So is that really an advantage to having the triplet as compared to just doing standard nivo + ipi?   We do see that it manifests in a slightly lower rate of grade 3/4 immune-related adverse events, at 39%. That's a little bit lower than what we'd expect for standard nivo + ipi. But again, I think that that emphasizes to me the possibility that some efficacy was left on the table by using this very low dose ipilimumab regimen. I think that's really a concern. It's not clear to me that these triplet data really differentiate from what we'd expect with the already approved regimen of nivo + ipi. Therefore, it makes it difficult to think about how would we really want to move this regimen forward, or should there be more work done about dose and schedule to optimize how we might want to do this?  Dr. Diwakar Davar: As far as triplet therapy in the context of frontline metastatic melanoma, meaning triplet immune therapy, because there are at least several targeted therapy triplets that are FDA-approved, [but] not necessarily widely utilized. How would you summarize the future for triplet therapy? Do you think it's potentially attractive? Do you think it's very attractive with some caveats? Dr. Jason Luke: Well, I think it's attractive, and we have 3 independently active agents. And so I do think it's a priority for the field to try to figure out how we could optimize the therapy. We've had such a revolution in melanoma oncology, talking about 7.5-year median survival from CheckMate-067, but that still implies that 7.5 years, half the patients have passed away. There's more to do here. And so I do think it should be a priority to sort this out. I guess I would be cautious, though, about advancing this regimen directly to a phase 3 trial because it doesn't seem clear to me that this is optimized in terms of what the outcome could be. If we're willing to tolerate higher rates of toxicity from other dose schedules of nivo-ipi alone, then I think we should do a little bit more here to potentially explore the space that might be possible to increase that overall response rate a little more without getting into a completely exaggerated toxicity profile that would be unacceptable. So, I do think it's exciting, but there’s possibly more to do before really think about going big time with this. Dr. Diwakar Davar: Great. So now we'll switch gears and move from frontline metastatic melanoma to the second line and beyond looking at a new agent and contextualizing the effects of that actually in the frontline settings. So Abstract 9505 describes the efficacy and safety of lifileucel, which is essentially autologous tumor-infiltrating lymphocyte cell therapies, also known as TIL, in combination with pembrolizumab in patients with ICI naive, so not necessarily pretreated, but ICI naive metastatic or unresectable melanoma. This is data from the IOV-COM-202 Cohort 1A oral abstract presented by Dr. Thomas and colleagues. In this abstract, Dr. Thomas and colleagues are presenting data from the 1A cohort, which is the phase 2 portion of the frontline trial that is evaluating autologous TIL with pembro in checkpoint inhibited naive metastatic melanoma.  By way of background, TIL is FDA approved on the basis of several cohorts from a phase 2 trial. The data has been presented multiple times now by Drs. Sarli, Chesney, and multiple colleagues of ours. And essentially autologous TIL, which is generated from a surgical procedure in which a patient undergoes a surgery to extract a tumor from which T cells are then grown after ex vivo expansion and rapid expansion protocol. The entire procedure was essentially pioneered by several colleagues at the NCI, primarily Dr. Steve Rosenberg, and this approach produces objective response rates of approximately 31% to 36%. And the most recent publication demonstrated that at median follow up of approximately 2 years, the median duration of response was not reached. The median OS was about 14 months and PFS was about 4 months or so. So, can you contextualize the results of the abstract in the frontline setting? And then we'll talk a little bit about where we think this is going to go. Dr. Jason Luke: So I think this is a timely study given the recent approval. And in the abstract presented here, we see an early data cut from the PD-1 naive study, as you alluded to. So here we had 22 patients and distributed across various states of advanced melanoma. Ten out of the 22 had M1C, but there also were smatterings of earlier M1A and M1B at 18.2% and 9.1%. So this is important, as we think who the treatment population is that's going to be optimized with a TIL procedure. The median sum of diameters, meaning how much tumor burden the patients have, was about 5.5cm, and I'll note that that's a relatively modest amount of tumor burden, albeit not that unusual for an early-stage trial. So of the patients that participated, 8 had BRAF mutations so that's 36%. That's not that high, but it's reasonable. And I think the important overlying number, the response rate so far in the study, with about 17 months of follow up, was 63.6%, and that includes 22% or 23% having complete response. So those are interesting data.  And another point that was made in the abstract, which we've all seen, is that responses to TIL, all of immunotherapy but especially TIL, do seem to mature over time, meaning they deepen over time. So it's possible the response rate could go up some extent as we watch this study advance. So I think these are exciting data on some level. Also, a 63.6% response rate sounds pretty impressive, but we do have to put that in the context of a double checkpoint blockade, which we just got done discussing, gives you almost a 60% response rate, 59% response rate. So then the question really is: Is it worth the amount of effort that we could go into generating a TIL product in a treatment naive patient, and put them through the lymphodepletion that is associated with TIL and the high dose interleukin 2 treatment that accompanies the reinfusion of the TIL, if you're going to get a response rate that's roughly the same as what you would get if you gave them off the shelf nivo plus ipilimumab?  At this point it's a little bit hard to know the answer to that question. I think it could be possible that the answer is yes, because we don't know exactly which populations or patients are most likely to benefit from each of these therapies. And if it could be teased out who's not going to benefit to nivo + ipi from the get-go, then of course, we would want to offer them a therapy that has that frontline potential, durable, long-term response. But I have to say, on a one-to-one with TIL therapy, you get a lot of toxicity initially with the treatment; with nivo + ipi on the back end, you get a fair amount of toxicity with the treatment. How are we going to judge those two things? And I think we probably need a larger dataset to really have a good handle on that.  So these are interesting early data, but it's not totally clear to me that even if this holds up all the way through the trial, and we're going to talk about the design of the registration trial here in a second, a 60% response rate on its own without further biomarker stratification is a little bit hard for me to see in clinical practice why we would want to do that, given we can already just go off the shelf and give checkpoint inhibitors. Dr. Diwakar Davar: So that brings us to TILVANCE-301. So TILVANCE is a phase 3 trial. It's a registration intent trial by our Iovance colleagues evaluating the pembro-TIL regimen versus pembrolizumab alone. So in this phase 3 trial, approximately 670 patients will be randomized to either arm A, which is lifileucel + pembro. And in this arm A, patients are going to be getting lifileucel with the tumor resection, non-myeloablative lymphoid depletion, the lifileucel and abbreviated course of high-dose IL-2, and thereafter, continued pembro for the study mandated duration versus arm B, where patients will be getting just pembrolizumab monotherapy per label. Arm B patients, per the design, may cross over to receive TIL monotherapy at the time of central-blinded, radiology-confirmed disease progression.   The study design otherwise is fairly routine and, per most of our registration trials these days, patients have actually been permitted to receive neoadjuvant and adjuvant therapy, including checkpoint inhibitors, as long as the receipt of the therapy was more than 6 months prior to the inclusion of the patient in that registration trial. The dual primary efficacy endpoints as stated are BICR-assessed objective response rate as well as PFS, and the key secondary endpoint is overall survival.   So Jason, what are your thoughts on the study design and potentially the regulatory implications, particularly given, one, the control arm of pembro monotherapy, and two, the role of TIL crossover to receive TIL monotherapy at the time of BICR mandated progression for arm B? Dr. Jason Luke: So this goes to a few points that we've touched on already in the discussion here. When we think about the primary endpoints for this study, with one of them being overall response rate, one has to assume that that's a given that they would get that. I feel like that's a low bar. And we go back to that cross-trial comparison. If their results end up being that the response rates are about 60%, I don't know that that differentiates necessarily from what's already available in the field with combination immune checkpoint blockade. For the purposes of the study that would mean it's a positive study, so I think that would probably be good. But again, the comparator to pembrolizumab monotherapy, I think some of us would argue, isn't really consistent with what we would do with a patient in our clinic. So it's not that it's bad per se, but I think there's going to be a whole lot of cross-trial comparison. So if the study is positive, that would be good for getting the drug available. It's still a bit hard though, based on the preliminary data that I've seen, to imagine how this would have uptake in terms of utilization as a frontline therapy.  You alluded to the crossover, and I think there, the assumption is that patients who get TIL therapy as a second line perhaps would have an attenuated benefit. But I'm not sure that's really true. It certainly looks from the data that we have, like the patients who benefit most from TIL are going to be those who didn't respond to anti PD-1 in the front line. So I'm not sure how much difference there's going to be between first- and second-line TIL therapy, but those data will kind of wait to be seen. So I think it's an important study. Of course, the accelerated approval of TIL as a later line therapy is dependent on this trial being positive. So there is some risk that if this trial ended up not being positive, that that could have regulatory implications on the utility or availability of TILs, a subsequent line therapy. But all of these, I guess we'll have to wait to see the results. We do hope for a positive trial here, although I think it'll be nuanced to sort of interpret those data given that pembrolizumab monotherapy control arm.  Dr. Diwakar Davar: Fantastic. So we've learned a lot about TIL, both its use in the second-line setting and this very exciting but potentially risky frontline trial that is ongoing at some centers in the United States and certainly a lot of ex-U.S. enrollment.   So we'll now pivot to a related product which actually belongs to a much larger class of agents that are antigen specific T-cell therapies in a variety of different formats. And that is Abstract 9507, which is the “Phase 1 safety and efficacy of IMC-F106C, a PRAME × CD3 ImmTAC bispecific, in post-checkpoint cutaneous melanoma (CM).” Now, in this abstract, Dr. Omid Hamid and colleagues reported the results of this phase 1 trial. As a disclosure, I'm an investigator and the last author on this manuscript. Jason, it would be important for our audience, for us to maybe firstly, outline the PRAME as a target, and then the ImmTAC as a platform prior to discussing these results. So let's start with the target PRAME, which I think is a target that you know well. So why don't you start with the target and we'll talk a little bit about that and then the platform? Dr. Jason Luke: Yeah, so I think for the audience, being aware of PRAME, or the Preferentially Expressed Antigen in Melanoma, is going to be quite important moving into the future. So PRAME as a therapeutic target is a cancer testis antigen that's overexpressed in tumor tissues. And of course the name has melanoma in it, but it's not uniquely present in melanoma. So the expression patterns of PRAME as a target are very high in melanoma. So in cutaneous disease, this is upwards of almost 100%, somewhere between 95% and 100%, in metastatic melanoma tissues. And PRAME has several different roles on a molecular level, although I don't think for our purposes here, it's so much important to be aware of them, but rather that this is a very highly expressed target, which then can make it attractive for using T cell receptor-based therapies. And so in the case we're talking about here on the ImmTAC platform, that's a CD3 PRAME×CD3 bispecific approach. But of course there are other approaches that can also be taken, such as TCR T cells that directly go after PRAME itself. Dr. Diwakar Davar: Let's now talk about the platform and how it differs from some of the other antigen targeting platforms that you have just alluded to. I think the Immtac platform is basically a fusion protein comprising engineered TCRs with a CD3 specific short chain variable fragment. And then the engineered TCR therefore binds antigens in an HLA dependent fashion. But you know quite a lot about some of these alternative platforms, and I think it'll be important to contextualize for the audience the difference between ImmTAC, which is a prototype drug that is already approved in the context of tebentafusp. But how does this differ from some of the other more nuanced platforms, such as the Immatics TCR or TCR platform and TScan TCRT nanoplasmonic platform.  Dr. Jason Luke: Right. So the ImmTAC platform as alluded to is already approved on the market with tebentafusp, which is the gp100-CD3 bispecific molecule. And the advantage of that approach is infusion off the shelf of a drug. The downside of it is that it is a weekly dosing strategy as it stands now. And there are some complicated disease kinetics associated with treatment response, which we'll come back to in the context of the PRAME bispecific. Those are, in contrast with T-cell receptor-transduced T cells, as an alternative strategy, which is a form of adopted cell transfer. So we just got done talking about TIL therapy, which of course, is trying to take lymphocytes out of the tumor and grow them up and then give them back. Here with TCR-transduced T cells, we're talking about taking leukopak from the blood and then using different transfection approaches to try to insert into the lymphocytes of the patient a T cell receptor that recognizes to a certain cancer antigen, in this case, PRAME.  So you alluded to a couple of different companies that have different platforms to do this. Immatics has a molecule called IMA 203, for which there have been data disclosed in the past year, again showing some very interesting responses in patients who have highly refractory melanoma. That process, though, again, does require lymphodepletion before you reinfuse the cells. Again, in contrast, the ImmTAC, which is an off the shelf revenue administer, there you have to make the product and then bring the patient back, lymphodeplete, and give the cells back. Immatics platform uses a viral transfection vector. The T scan approach that you alluded to before uses an approach of a mixed system on multiple HLA backgrounds to try to get past HLA-A*02:01 only, and in this case, uses a plasmid-based transfection syndrome that perhaps can be more broadly utilized given the lack of a lentiviral vector.   So this is a complicated area of technology that starts to get into immune engineering, and I think for the purposes of this discussion, we don't want to belabor it. But both of these technologies, talking about the CD3 bispecific with the off the shelf aspect of it and the adoptive cell transfer, each of these using a T cell receptor-based therapy to try to go after PRAME, I think have very high upsides, and I think we'll initially see it in melanoma over the next year or so. But this is likely to be relevant to multiple tumor types beyond melanoma.  Dr. Diwakar Davar: So let's discuss the results of this phase 1 trial. IMC-F106C, like all other ImmTAC, is administered intravenously and does require step-up dosing. You alluded to the fact that the tebentafusp was approved, and it's one of those drugs that is fortunately otherwise administered weekly, which can be difficult for the patient and requires at least the patient spend the first 3 doses overnight under some kind of monitoring, whether it's in the hospital or extended outpatient monitoring, for at least 23 hours. The efficacy of this agent and this platform appears to be surprising in that you tend to see a relatively low RECIST response rate. We'll have you comment a little bit on why that is the case and what may be the role of ctDNA, as opposed to conventional RECIST in assessing response.   At least in this trial, they mandated pre-testing, but did not require it for study enrollment. And pre-positivity was defined using immunohistochemistry with a relatively low H-score of 1%. And the molecular response definition was a 0.5 log or a 68% ctDNA reduction just prior to the first imaging assessment. So how do you contextualize the results? But maybe before you talk a little bit about the results, the ctDNA aspect, that was a recent publication by Drs. Rich Carvajal, Alex Shoushtari, and I think you are also involved in that.  Dr. Jason Luke: So, I think an interesting observation around tebentafusp has been that ctDNA may be a better predictor of long-term outcomes. And how you define ctDNA response is still something that the field is grappling with, albeit that I think is going to be an important consideration as we think about these novel therapies, these ImmTACs and other CD3 engagers moving into the future. But for the purposes of the abstract here, we see that in the population of patients treated, there were 46 patients with cutaneous melanoma. The majority got monotherapy with IMC-F106C, and that's the PRAME bispecific. So 40 patients that got monotherapy and six who got a combination with checkpoint inhibitor. All these patients had prior treatment with immunotherapy, and most of them had PD-1 and CTLA-4 antibody with a small spanner that also had BRAF inhibitors.  In terms of that PRAME testing that you alluded to, based on the immunohistochemistry H-score greater than 1%, 35 out of 40 patients were positive, so they defined 5 as negative. And we could come back if we have time, but there are other ways to do PRAME testing as well that I think may become unique for different agents, maybe an important biomarker. In the data, 31 out of the 46 patients were RECIST evaluable. The outcomes of those patients were to note that the response rate was 13%, which was four partial responses. But 35% of patients had tumor regression with a disease control rate at 65%. It was clear that there was an enrichment by PRAME positivity for both progression free and overall survival. So those patients who had obvious positivity essentially had a doubling of the PFS and more than the doubling of the OS, 2.1 to 4.1 months for TFS and landmark OS, 40% to 94%. So I think these are quite intriguing data.  It does suggest that for the vast majority of patients, we do see some induction of the antitumor effect, albeit that RECIST might undercall the effect. And so this may become another area where the ctDNA monitoring might be able to help us to understand who is likely to have really long-term benefit from this therapy. And given the number of emerging treatments that we have for melanoma, we might be able to really focus in on that group of patients in terms of optimizing how we would use this drug moving into the future. Dr. Diwakar Davar: So you talked about a response rate, and at first glance, this response rate is a little underwhelming. We're talking about 4 out of 31 RECIST evaluable patients, 13%. So it's in the double digits, but barely. So how enthusiastic are you about the results? How does it contrast with at least the publicly known data from other brain targeting approaches, such as the IMA203 agent, understanding that while they may be all targeting somewhat the same target, they are actually extraordinarily different platforms. One’s off the shelf, one’s highly customized. How do you contextualize the results? How would it contrast with other cellular approaches?  Dr. Jason Luke: I think it's important, again, to emphasize the point you made, which is that they're very different kinds of treatments. So even though they both target PRAME, they're going to be differently useful, and they could be quite useful for different groups of patients. And so here we see that there is a subfraction of patients who are deriving long-term benefit. And we commonly have an argument in our field about, is overall response rate really a useful monitor that describes a patient-centric outcome? While, of course, patients like to know their tumors are shrinking, what they want the most is for the tumors not to get worse and for them not to pass away from cancer. So I think I'm enthusiastic about these results, but emphasizing the point that we need to better understand who is going to benefit the most from this CD3 bispecific PRAME approach and how we're going to be able to harness that into long term benefit for patients because there's no doubt that an off the shelf therapy has a high degree of value relative to adoptive cell transfer, which sort of requires a big wind up.   So when you say, what does it contrast with? Well, the data for IMA203 has shown more than a 50% response rate in patients with more than 5 lines of therapy for metastatic disease. That really looks quite exciting. And several of those patients are now out for quite an extended period, meaning 2 years or more given only a single dose of IMA203. But again, the caveat being, you have to make the cell product for the patient, and that takes time. You lymphodeplete the patient, not all patients can tolerate that in the refractory disease setting, and then they have to be able to tolerate the reinfusion of the cells. And so this drug, IMC-F106C, looks very promising. Moving into the earlier phase trial that we'll talk about, I think the TCR T cell program has a lot of upsides for patients, especially with refractory disease. And so I think these two different approaches are really on parallel tracks. They both target PRAME, but I don't think they necessarily need to be compared one to one, as if they're going to go head-to-head with each other. Dr. Diwakar Davar: So now we'll talk a little bit about the frontline setting, because on the basis of some of these results, Immunocore is now exploring IMC-F106C frontline melanoma. This trial is actually being presented as a trial in progress at this meeting by Georgina Long and colleagues. Some of us are co-authors in that abstract. And in this study, HLA-A*02:01 positive patients with advanced unresectable melanoma will be randomized one to one to the combination of IMC-F106C, which actually, I think after this meeting will be known as bre-ni in combination with nivolumab versus nivolumab regimens, which will either be nivo or nivo-rela, investigators choice and likely dependent on region. So what do you think of the challenge of this trial? We talked about some of the challenges of the TILVANCE trial earlier. But what is going to be the challenge of this trial and in this setting, particularly given the response rates that we've seen so far? Dr. Jason Luke: Yeah, so, similar to comments we had before, thinking about what the optimal control arm is for a study like this is difficult, and so that'll be important as we think about interpreting the results. One has to assume for the purpose of this conversation that it is a positive trial, and that adding the PRAME bispecific theory does lead to an improvement in progression free survival relative to those in checkpoint alone approaches. And I think the magnitude of that difference is going to be of some relevance. And then I think importantly, also figure out who needs this treatment and who's going to benefit long term are going to be really important considerations.  We alluded to how this drug requires an intensive dosing period at the get go, and so telling patients that they need to come in weekly or bi-weekly initially for some number of weeks before they switch to a longer-term intermittent regimen, that comes with real world considerations for patients, their families, their finances, etc. So the benefit has to be clearly obvious that makes it worthwhile doing that, again, because a default could be giving drugs that we've had for 10 years with the nivolumab and ipilimumab. So there's going to be a lot of cross-trial comparison that is going to necessarily have to take place here to think about what these results really mean in the context of other available therapies.  I think the study is reasonable to do. I think this is a very active agent. There's no doubt there's a subset of patients who seem to benefit a lot from it. And I would just emphasize the point that that's probably going to be the most important thing to really drill down on is under the assumption there's a positive trial, we need to know who those people are so we could optimize giving this kind of a treatment to them. Dr. Diwakar Davar: I guess one important point to underscore what Jason said about potential predictive biomarkers, I think as part of the presentation, Dr. Hamid and colleagues will be talking about a candidate predictive biomarker of this agent, which is potentially class specific and not necessarily agent specific of a T cell signature that potentially could define patients who are more likely to benefit from this agent.  So, Jason, as always, thank you for sharing your expertise and insights with the team today. We certainly look forward to catching up again for our wrap up episode after the annual meeting where we'll talk about some of the data that we could not talk about, particularly the late breaking abstracts and other key advances that will shape the future of, certainly the field of immunotherapy and melanoma, potentially the field of cancer immunotherapy at large. Dr. Jason Luke: Oh, thanks very much for the opportunity. Dr. Diwakar Davar: And thank you to our listeners today. You'll find the links to the abstracts discussed today in the transcript of this episode. And finally, if you value the insights that you hear on this podcast, please take a moment to rate, review, and subscribe wherever you get your podcast. So thank you, and we'll see you soon.   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.   Follow today’s speakers:   Dr. Diwakar Davar   @diwakardavar   Dr. Jason Luke   @jasonlukemd      Follow ASCO on social media:    @ASCO on Twitter   ASCO on Facebook   ASCO on LinkedIn      Disclosures:       Dr. Diwakar Davar:     Honoraria: Merck, Tesaro, Array BioPharma, Immunocore, Instil Bio, Vedanta Biosciences    Consulting or Advisory Role: Instil Bio, Vedanta Biosciences    Consulting or Advisory Role (Immediate family member): Shionogi    Research Funding: Merck, Checkmate Pharmaceuticals, CellSight Technologies, GSK, Merck, Arvus Biosciences, Arcus Biosciences    Research Funding (Inst.): Zucero Therapeutics    Patents, Royalties, Other Intellectual Property: Application No.: 63/124,231 Title: COMPOSITIONS AND METHODS FOR TREATING CANCER Applicant: University of Pittsburgh–Of the Commonwealth System of Higher Education Inventors: Diwakar Davar Filing Date: December 11, 2020 Country: United States MCC Reference: 10504-059PV1 Your Reference: 05545; and Application No.: 63/208,719 Enteric Microbiotype Signatures of Immune-related Adverse Events and Response in Relation to Anti-PD-1 Immunotherapy       Dr. Jason Luke:    Stock and Other Ownership Interests: Actym Therapeutics, Mavu Pharmaceutical, Pyxis, Alphamab Oncology, Tempest Therapeutics, Kanaph Therapeutics, Onc.AI, Arch Oncology, Stipe, NeoTX    Consulting or Advisory Role: Bristol-Myers Squibb, Merck, EMD Serono, Novartis, 7 Hills Pharma, Janssen, Reflexion Medical, Tempest Therapeutics, Alphamab Oncology, Spring Bank, Abbvie, Astellas Pharma, Bayer, Incyte, Mersana, Partner Therapeutics, Synlogic, Eisai, Werewolf, Ribon Therapeutics, Checkmate Pharmaceuticals, CStone Pharmaceuticals, Nektar, Regeneron, Rubius, Tesaro, Xilio, Xencor, Alnylam, Crown Bioscience, Flame Biosciences, Genentech, Kadmon, KSQ Therapeutics, Immunocore, Inzen, Pfizer, Silicon Therapeutics, TRex Bio, Bright Peak, Onc.AI, STipe, Codiak Biosciences, Day One Therapeutics, Endeavor, Gilead Sciences, Hotspot Therapeutics, SERVIER, STINGthera, Synthekine    Research Funding (Inst.): Merck , Bristol-Myers Squibb, Incyte, Corvus Pharmaceuticals, Abbvie, Macrogenics, Xencor, Array BioPharma, Agios, Astellas Pharma , EMD Serono, Immatics, Kadmon, Moderna Therapeutics, Nektar, Spring bank, Trishula, KAHR Medical, Fstar, Genmab, Ikena Oncology, Numab, Replimmune, Rubius Therapeutics, Synlogic, Takeda, Tizona Therapeutics, Inc., BioNTech AG, Scholar Rock, Next Cure    Patents, Royalties, Other Intellectual Property: Serial #15/612,657 (Cancer Immunotherapy), and Serial #PCT/US18/36052 (Microbiome Biomarkers for Anti-PD-1/PD-L1 Responsiveness: Diagnostic, Prognostic and Therapeutic Uses Thereof)    Travel, Accommodations, Expenses: Bristol-Myers Squibb, Array BioPharma, EMD Serono, Janssen, Merck, Novartis, Reflexion Medical, Mersana, Pyxis, Xilio