Immunotherapy at ASCO24: NADINA and Other Key Studies

ASCO Daily News

Dr. Diwakar Davar and Dr. Jason Luke discuss advances in the neoadjuvant immunotherapy space that were presented at the 2024 ASCO Annual Meeting, including promising outcomes in high-risk melanoma from the NADINA trial, as well as other new treatment options for patients with advanced cancers.

TRANSCRIPT

Dr. Diwakar Davar: Hello and welcome to the ASCO Daily News Podcast. I'm your guest host, Dr. Diwakar Davar, and I am an associate professor of medicine and the clinical director of the Melanoma Skin Cancer Program at the University of Pittsburgh's Hillman Cancer Center. I am delighted to have my colleague and friend Dr. Jason Luke on the podcast today to discuss key late-breaking abstracts and advances in immunotherapy that were presented at the 2024 ASCO Annual Meeting. Dr. Luke is an associate professor of medicine, the associate director of clinical research, and the director of the Cancer Immunotherapeutic Center at the University of Pittsburgh Hillman Cancer Center.

You will find our full disclosures in the transcript of this episode.

Jason, it's always a pleasure to hear your insights on the key trials in these spaces and to have you back as a guest on this podcast that highlights some of the work, especially advances, that were just presented.

Dr. Jason Luke: Well, thanks very much for the invitation. I always love joining the podcast.

Dr. Diwakar Davar: We'll start very quickly by talking about some advances and really interesting things that happened both in the context of melanoma but also in immunotherapy in general. And we'll start with what I think was certainly one highlight for me, which was LBA2, the late-breaking abstract on the NADINA trial. It was featured in the Plenary Session, and in this abstract, Dr. Christian Blank and colleagues reported on the results of this phase 3 trial of neoadjuvant ipi-nivo. This is the flipped dose of ipi1/nivo3 versus adjuvant nivolumab in PD-1 naive, macroscopic, resectable, high-risk stage 3 melanoma.

By way of background, neoadjuvant immunotherapy for those listening is an area of increasing interest for drug developers and development for both approved and novel agents. Neoadjuvant immunotherapy has been studied with multiple approved agents, including PD-1 monotherapy, PD-1 LAG-3, PD-1 CTLA-4, T-VEC, as well as investigational agents and multiple randomized and non-randomized studies. The benchmark pathologic response rates with these agents range from 17% PCR with PD-1 monotherapy, 45% to 55% PCR with PD-1 CTLA-4 combination therapy, and slightly higher 57% PCR with PD-1 LAG-3 has recently reported by Dr. Rodabe Amaria from MD Anderson. However, as we embark on phase 3 comparisons for various neoadjuvant compared to adjuvant immunotherapy trials and combinations, we're increasingly moving towards event-free survival as the primary endpoint for neoadjuvant versus adjuvant studies. And this was most recently studied in the context of SWOG S1801, a study that was led by Dr. Sapna Patel.

So, Jason, before we start on NADINA, can you briefly summarize the SWOG S1801 trial and the event-free survival statistic reported by Dr. Patel and her colleagues?

Dr. Jason Luke: Well, absolutely. And these data were reported at ESMO about two years ago and then in the New England Journal last year. The S1801 study answered a very simple question: What would happen if you took three of the doses of standard adjuvant therapy with pembrolizumab and moved them prior to surgery? And on a high level, the study is as simple as that. And many of us were somewhat skeptical of this trial design because we thought that just moving the doses earlier may not actually have a major impact.

In the study, you alluded to the event-free survival statistic, and that alludes to what was considered an event. And so, without reading all of it, there were several different aspects that were included in terms of time, based on the date of randomization until the first of a series of events, such as disease progression, toxicity from treatment, if the patient was unable to go to surgery or had surgical complications, or if they had delay in starting the adjuvant therapy due to toxicity, and obviously, recurrence of melanoma or death from any cause. In that context, merely moving the 3 doses of pembrolizumab to the neoadjuvant setting saw an improvement in this two-year event free survival to 72% for the neoadjuvant therapy compared to 49% for the adjuvant therapy. That was quite an outstanding change. And again, noting the power of neoadjuvant treatment, really dictating the impact of anti PD-1, again, just with 3 doses moving from adjuvant into the neoadjuvant setting, and I think all of us were somewhat surprised to see that magnitude of a benefit. But it set up the current study very well, where we now look at combination therapy.

Dr. Diwakar Davar: So let's move on to the phase 3 NADINA trial. Do you want to perhaps discuss the study design, particularly focusing on the EFS primary endpoint and maybe also touching on the different schedules? So, SWOG S1801 was a neoadjuvant study of 3 cycles of pembrolizumab and how did that compare and contrast to the neoadjuvant combination that was studied in NADINA?

Dr. Jason Luke: Well, as you alluded to, NADINA investigated the regimen of nivolumab plus ipilimumab and compared that against adjuvant therapy with nivolumab alone. So, in the study, as you alluded, the dose and schedule of the two drugs used was nivolumab at 3 milligrams per kilogram, and ipilimumab with 1 milligram per kilogram. That was based on a series of signal finding and safety studies that had been previously done by the same group of authors identifying that as the optimal treatment regimen. And it's worth noting that's slightly different than the labeled indication that's generally used for those same drugs for metastatic melanoma, albeit that the NCCN also endorses this schedule. So, in the trial, 423 patients were randomized, 1:1 to receive either neoadjuvant therapy with those 2 doses of nivolumab plus ipilimumab as compared with standard adjuvant therapy with nivolumab following surgery.

Now, one interesting tweak was that there was an adaptive nature to the study, meaning that patients had a fiducial placed at the index lymph node, and after the neoadjuvant therapy in that arm, that lymph node was removed. And if the patient had a major pathological response, they did not go on to receive the adjuvant portion of the treatment. So it was adaptive because those patients who did very well to the neoadjuvant did not require the adjuvant portion. And in those patients who did not achieve a major pathological response, they could go on to have the adjuvant therapy. And that also included the BRAF therapy for those whose tumors were BRAF mutants.

It's also worth pointing out that the definition of event free survival was slightly different than in the S1801 study that was alluded to just a second ago. And here, EFS was defined from the date of randomization until progression due to melanoma or due to treatment. So that's slightly different than the definition in the S1801 trial. So, a somewhat complicated study, but I really applaud the authors because I think this study does mirror what we would likely be doing in actual clinical practice.

Dr. Diwakar Davar: So, just to briefly summarize the efficacy, and then to get your comments on this, the path response, the PCR rate was 47%. The major pathologic response rate, which is the proportion of patients with between 0% to 1/10% of residual viable tumors, was about 12%. And for a major pathologic response rate of 0% to 10% of 59%. And then the rest of the patients had either pathologic partial response, which was 10% to 50%, or pathologic non response or 50% or greater residual viable tumor, all assessed using central pathology grades. The one year RFS was 95% in the FDR patient population versus 76% in the pathologic partial response patient population, 57% in the pathologic non response patient population. So how do you view these results? Can you context the FDR rates and the EFS rates from NADINA relative to nivo-rela and also potentially SWOG 1801?

Dr. Jason Luke: Well, I think these are very exciting results. I think that for those of us that have been following the field closely, they're actually not especially surprising because they mirror several studies that have come before them. When we put them in context with other studies, we see that these rates of major pathological response are consistent with what we've seen in phase 2 studies. They're relatively similar. Or I should say that the results from nivolumab and relatlimab, which was also pursued in a phase 2 study of somewhat similar design, are somewhat similar to this. So, combination immunotherapy does look to deliver a higher major pathological response than pembrolizumab alone, as was known in S1801. Which of course, the caveat being is these are cross control comparisons that we need to be careful about. So I think all of these are active regimens, and I think adding a second agent does appear to enhance the major pathologic response rates. When we look at the event free survival, we see something similar, which is that numerically it looks to be that combination immunotherapy delivers a higher event free survival rate. And that looks to be rather meaningful given the difference in the hazard ratios that were observed between these various studies. And here in the NADINA study, we see that 0.3 hazard ratio for EFS is just extremely impressive.

So the abstract then, from ourselves, out of these specific studies, what does this mean more broadly in the real world, where patients exist and the rest of the landscape for clinical trials? I think we can't take enough time to stop for a second and just think about what a revolution we've come forward in with immune checkpoint blockade and melanoma. When I started my career, now, more than 15 years ago, melanoma was the cancer that made cancer bad. And now here we say, in the highest risk of perioperative patients, we can deliver 2 doses of nivolumab and ipilimumab, and essentially half of the patients then don't need to go on, and more than half the patients don't need to go on to have a full surgery and don't need adjuvant therapy. And from what we could tell of a very, very low risk of every heavy recurrence of melanoma. Of course, there's the other half of patients where we still need to do better, but these are just fantastic results and I think highly meaningful for patients.

In the context of ongoing clinical trials, another abstract that was presented during the meeting was the update to the individualized neoantigen therapy, or V940 with pembrolizumab or against pembrolizumab alone. That's the KEYNOTE-942 study. In that study, they presented updated data at two and a half years for relapse free survival, noting a 75% rate without relapse. So those results are also highly intriguing. And these are in a similar population of very high risk patients. And so I think most of us believe that neoadjuvant therapy with this study in NADINA is now confirmed as the priority approach for patients who present with high-risk stage 3 disease. So that would be bulky disease picked up on a scan or palpable in a clinic. I think essentially all of us now believe patients should get preoperative immunotherapy. We can debate which approach to take, and it may vary by an individual patient's ability to tolerate toxicity, because, of course, multi agent immunotherapy does have increased toxicity relative to anti PD-1 alone. But we'll have to wait now for the full phase 3 results from the V940 individualized neoantigen therapy. And if those come forward, that will be an extremely attractive approach to think about for patients who did not achieve a major pathological response to neoadjuvant therapy, as well as of course to the other populations of patients with melanoma where we otherwise currently give adjuvant therapy stage 2B all the way through stage 4 resected. It’s an amazing time to think about perioperative therapy in melanoma.

Dr. Diwakar Davar: So this is clearly outstanding data, outstanding news. Congratulations to the investigators for really doing what is an investigative initiated trial conducted across multiple continents with a huge sample size. So this clearly appears to be, at this point in time at least, a de facto standard. But is this going to be FDA-approved, guideline-approved, or is it possible in your mind?

Dr. Jason Luke: Well, that's an interesting question. This study was not designed with the intent to necessarily try to register this treatment regimen with the FDA. One would have to take a step back and say, with how powerful these data appear, it sort of seemed like it would be too bad if that doesn't happen. But all the same, I think the community and those of us who participate in guideline recommendations are fully supportive of this. So, I think we will see this move into compendium listings that support insurance approval, I think, very, very quickly. So, whether or not this actually becomes formally FDA approved or is in the guidelines, I think this should become the standard approach that is considered for patients, again presenting with high-risk stage 3 disease.

Dr. Diwakar Davar: Fantastic. So now we're going to go in and talk about a slightly different drug, but also from the melanoma context, and that is the safety and efficacy of RP1 with nivolumab in the context of patients with melanoma who are PD-1 failures. So, this is Abstract 9517. And in this abstract, our academic colleagues essentially talked about these data, and we'll start by describing what RP1 is. RP1 essentially is a HSV-1 based oncolytic immunotherapy. And RP1 expresses GM-CSF as well as a fusogenic protein, GALV-GP-R-. And in this abstract, Dr. Michael Wong from MD Anderson and colleagues are reporting the results of IGNYTE, which is a phase I trial of intratumoral RP1 co-administered with systemic nivolumab in patients with advanced metastatic treatment refractory cutaneous melanoma. And the data presented in this abstract represents data from a registration directed, abbreviated as RD, registration directed cohort of RP1 plus nivolumab in PD-1 refractory melanoma. So, let's start with the description of the cohort.

Dr. Jason Luke: Right. So, in this study, there were a total of 156 patients who were presented, and that included an initial safety and dose finding group of 16, as well as the RD cohort, as you noted, of 140 patients. And it's important to point out that this was a cohort that was selected for a very strict definition of progression on anti PD-1, or a combination immunotherapy as their immediately prior treatment. So, all of the patients in the cohort had exposure to anti PD-1, and 46% of them had anti PD-1 plus anti CTLA4, nivolumab and ipilimumab as their immediately prior therapy. This was also a group of relatively high-risk patients when one considers stage. So, within the stage 4 population, the entry here included 51% who had stage M1B, C, and D melanoma. And that is worth pointing out because this is an injectable therapy. So, trials like this in the past have tended to be biased towards earlier stage, unresectable or metastatic melanoma, meaning stage 3B, 3C, 3D and then stage 4m1a. Again, to emphasize the point here, these were pretreated patients who had a strict definition of anti PD-1 resistance, and over half of them, in fact, had high-risk visceral metastatic disease.

In that context, it's very interesting to observe that the overall response rate was described in the total population, as 31%, and that included 12% who achieved complete response. And so, again, to make sure it's clear, we're talking about a treatment where the oncolytic virus is injected into one or multiple sites of recurrent disease, and then the patients administer nivolumab as per standard. And so, I think these data are quite intriguing. Again, such a high- risk population and their maturity now, with a follow-up of over a year, I think, makes this look to be a very interesting treatment option.

Dr. Diwakar Davar: I guess on that topic of mature follow-up, it probably would be important for us to inform our audience that the top line data for the primary analysis was actually just released, I think, earlier today, and wherein the central confirmed objective response rate was 34% by modified RECIST and 33% by RECIST, clearly indicating that these responses, as you noted, very treatment refractory patient population, these responses were clearly very durable. So, you mentioned that there were responses seen in uninjected visceral lesions, responses seen in both PD-1 and PD-1 CTLA-4 refractory patients. Can you talk a little bit about the response rate in these high-risk subgroups, the uninjected visceral lesions, the patients who had both combination checkpoint and epidural refractory response rate by primary PD-1 resistance.

Dr. Jason Luke: Sure. You know, I think, again, to emphasize this point in the study, we saw that there were responses in the non-injected lesions, and I think it's really important to emphasize that. Some have referred to this as a putative abscopal like effect, similar to what is described in radiation. But it implies that local treatment with the oncolytic virus is triggering a systemic immune response. In the higher risk patient population, we'll note that whereas the overall response rate in PD-1 refractory patients was 34%, in the combination of PD-1 and CTLA-4 refractory patients, the response rate was 26%. So, [this is] still very good. And when we looked at that split by stage, as I alluded to before, in the population of patients that had, what you might call earlier unresectable diseases, so 3B through 4A, the response rate was 38%, and in the stage 4 M1b through M1d, it was 25%. So slightly lower, but still very good. And that would be as expected, because, of course, the patients with visceral metastatic disease have more advanced disease, but those response rates look quite good. Again, looking at the combination refractory population as well as the more high-risk disease.

Dr. Diwakar Davar: So, clearly, these are very promising data and exciting times for multiple investigators in the field and the company, Replimune, as well. So, what are the next steps? I believe that a registration trial is planned, essentially, looking at this with the goal of trying to get this combination registered. Can you tell us a little bit about IGNYTE-3, the trial design, the control arm, and what you foresee this trial doing over the next couple of years?

Dr. Jason Luke: So, as this agent has been maturing, it's worth pointing out that the company that makes this molecule, called RP1, but I guess now we'll have to get used to this name vusolimogene oderparepvec as the actual scientific term, they have been having ongoing discussions with the FDA, and there is the potential that this agent could come forward on an accelerated path prior to the results being released from a phase 3 trial. That being said, the phase 3 confirmatory study, which is called the IGNYTE-3 study, is in the process of being launched now. And that's a study investigating this molecule in combination with nivolumab, as was alluded to earlier, and a randomized phase 3 design, where that combination is compared with a physician's choice, essentially a chemotherapy-based option.

In that study, it will be 400 patients with stage 3B through stage 4; patients will have progressed on anti PD-1, either as a combination or in sequence, and then come on the study to be randomized to either vusolimogene oderparepvec plus nivolumab versus that physician's choice. And the physician's choice includes chemotherapy agents, but also nivolumab plus relatlimab as another option, or an anti PD-1 monotherapy, if that's deemed to be a reasonable option by the treating investigator. And the primary endpoint of that study is overall survival. And unfortunately, in this highly refractory patient population, that's something that may not take long to identify with key secondary endpoints of progression free survival, as well as overall response rate. I'm quite enthusiastic about this study, given these data, which have now been centrally confirmed as you alluded to before. I think this is a very exciting area of investigation and really crossing my fingers that this may be perhaps the first locally administered therapy which does appear to have a systemic impact that can hold up in phase 3.

Dr. Diwakar Davar: Very, very, very exciting results. And I guess it's worthwhile pointing out that this company also has got, I think, multiple studies planned with both RP1 and cutaneous squamous cell carcinoma in a solid organ transplant patient population where single agent activity has already been reported by Dr. Migden at prior meetings, as well as a novel trial of potentially RP2 metastatic uveal melanoma.

So we'll now pivot to Abstract 6014. So, 6014 is a drug by a company known as Merus. Essentially, it's a very novel agent. Merus essentially is a company that is specialized in making bicyclics and tricyclics. And these are not bicycles or tricycles, but rather drugs that essentially are bispecific antibodies. And Merus essentially has come up with petosemtamab. I think we're going to have to figure out better names for all of these drugs at some point. But petosemtamab, or MCLA-158, essentially is a bicyclic, targeting both EGFR as well as LGR-5. So EGR-5, of course, is a known oncogenic driver in multiple tumor types, squamous, including non small cell lung cancer, cutaneous squamous cell carcinoma, but also head and neck squamous cell carcinoma. And LGR-5 essentially is leucine-rich repeat-containing G-protein coupled receptor 5, but it's a receptor in cancer stem cells and certainly highly expressed in head neck squam. And MCLA-158, or petosemtamab is a IgG one bispecific with ADCC-activity because of IgG1 backbone co-targeting EGFR and LGR5. Merus had earlier results that evaluated petosemtamab monotherapy. They defined the RP2D and second- and third-line head and neck blastoma patients with a respectable response rate of 37% investigator-assessed ORR with six months median DoR, and this was published by Ezra Cohen about a year or so ago.

In this abstract, Dr. Fayette and colleagues report on the results of the MCLA-158-CL01 trial, which is a trial of pembrolizumab plus petosemtamab in one front line head and neck squamous cell population. So maybe let's start with the description of the cohort. And it is a small trial, but we'll be able, I think, to dig into a little bit about why this might be exciting.

Dr. Jason Luke: Yes. So, as alluded to, it's not the biggest trial as yet, but there were 26 patients with anti PD-1 treatment naive head and neck squamous cell carcinoma. And all the patients in the study did receive, as you alluded to, pembrolizumab plus petosemtamab. Based on the label for pembrolizumab, all the patients in this study were PDL-1 positive. So that's one point that it’s worth pointing out to make sure that that's understood. This is the population of patients who would be expected to benefit from pembrolizumab in the first place. Now, in the abstract, they reported out only 10 response evaluable patients, but they updated that in the actual slides of presentation at the meeting. So among 24 patients that were alluded to, 67% were described as having had a response, although some of those were yet to be confirmed responses. And when it was evaluated by PDL-1 status, there didn't seem to be a clear enrichment of response in the PD-1 positive more than 20% group, as compared to the 1-19% group. That isn't especially surprising because that was a trend that one would see, presumably with pembrolizumab alone. But overall, I think these data are pretty exciting in terms of a preliminary study.

Dr. Diwakar Davar: You know, you mentioned that the objective response rate was high, almost 60-something%. The prognosis of these patients is generally poor. The OS is typically thought of as between 6-15 months. And based on KEYNOTE-048, which was led by Dr. Burtness and colleagues, the standard of care in the setting is pembrolizumab +/- platinum based chemotherapy regimens. Allowing for the fact that we only have 10 patients here, how do you think these results stack up against KEYNOTE-048? And you made a very important point earlier, which was, by definition, pembro is on label only for the CPS. So PDL-1 score, at least in head and neck squamous cell carcinoma CPS and not TPS. But in the CPS 1% or greater patient population, where pembro is on label, how do these results stack up against the KEYNOTE-048 results.

Dr. Jason Luke: Right. KEYNOTE-048 is considered the seminal study that dictates frontline treatment in head and neck cancer. And before we dive into this too far, we do want to acknowledge that here we're comparing 26 patients versus a phase 3 trial. So, we're not trying to get too far ahead of ourselves, but this is just a preliminary comparison. But in KEYNOTE-048, as you alluded to, two regimens were superior to chemotherapy. One was the pembrolizumab monotherapy, as well as pembrolizumab plus chemotherapy. So again, the study overall survival, of course, was much higher, the PDL-1 positive subgroup, which is what dictated the unlabeled use of this. But response to pembro monotherapy in that population of patients is still modest. We're talking about upwards of 20-30%. So, if you compare that to, again, preliminary evidence here from this trial of only 24 patients, that response rate of 60% seems extremely high. And so even if that were to come down somewhat in a larger data series of patients, that still looks to be quite promising as a treatment regimen, that might eventually even be chemotherapy sparing for this population of patients. I think this raises a lot of eyebrows that perhaps this dual targeting approach, EGFR and LDR-5, may bring something really important to the field that evolves it.

Dr. Diwakar Davar: So, what are the next steps for petosemtamab? You mentioned that the activity was interesting. Are we going to see a larger trial? Any thoughts on where things are going to go?

Dr. Jason Luke: Well, based on the phase 2 data of petosemtamab alone, even without pembrolizumab, the molecule had already been given fast track designation by FDA, which means allowing for greater communication between the drug sponsor in the FDA and designing a seminal study design. One would assume that this trial will be rapidly expanded quite greatly, perhaps to 100 or 200 patients, to try to flush out what the real response rate is in a more meaningful number of patients. But I think these data will probably also trigger the design and probably near-term evaluation or expedited acceleration of a phase III clinical trial design that would potentially validate this against the current standard of care. So, I'm pretty excited. I think we'll see a lot more about this agent in the relatively near future.

Dr. Diwakar Davar: So, finally, we'll pivot to the last abstract that we're going to talk about, which is Abstract 2504. It's a relatively interesting target, CCR8 monoclonal antibody. But this is the efficacy and safety of LM-108, and LM-108 is an anti CCR8 monoclonal antibody that is being developed by LaNova Medicine. And the results that are described, actually a pool set of results of combinations of LM-108 with anti PD-1, two separate anti PD-1, in patients with gastric cancer, mostly done ex-U.S., which is interesting because of this patient population, and it's a pool result of several, 3 phase 1 and 2 studies.

LM-108 is an Fc-optimized anti CCR8 monoclonal antibody that selectively depletes tumor infiltrating Tregs. The abstract reported a pooled analysis of three phase 1, 2 trials with 3 different NCT numbers that all evaluated the efficacy of LM-108 and anti PD-1 in patients with gastric cancer. So, let's start with the description of the cohort. Maybe, Jason, you can tell us a little bit about before you start, as you describe the cohort, sort of what we know, editorially speaking, about the difficulty with which Tregs depletion has been tried and obviously failed up until now in the tumor microenvironment.

Dr. Jason Luke: Right. I think that's a really interesting comment. And so, for decades, in fact, targeting regulatory T-cell to alleviate immune exclusion in the tumor microenvironment has been of interest in immuno-oncology. And in preclinical mouse models, it seems quite clear that such an approach can deliver therapeutic efficacy. However, by contrast, in human clinical trials, various different Treg depleting strategies have been attempted, and there's really little to no evidence that depleting Tregs from human tumors actually can deliver therapeutic responses. And by that we're referring to CD-25 antibodies. The drug ipilimumab, the CTLA-4 antibody, was punitively described as a Tregs depleter preclinically, but that doesn't seem to be the case in patients. And so, in that background, this is quite an eye raiser that an anti CCR8 antibody could be driving this effect. Now, before we talk about the results of this trial, I will point out, however, that given the Fc-optimization, it's entirely possible that the Tregs are being depleted by this mechanism, but that more could also be going on. Because Fc gamma RII binding by this antibody that could be nonspecific also has the potential to trigger immune responses in the tumor microenvironment, probably mediated by myeloid cells. So I think more to come on this. If this turns out to be the first meaningful Tregs depletor that leads to therapeutic efficacy, that would be very interesting. But it's also possible this drug could have multiple mechanisms.

So, having said all of that, in the clinical trial, which was a pooled analysis, like you mentioned, of LM-108 in combination with anti PD-1 of a couple different flavors, there were 48 patients treated either with LM-108, with pembrolizumab, or with toripalimab, which is another anti PD-1 antibody. On the drug combination was, generally speaking, pretty well tolerated, noting grade 3 treatment related adverse events in the range of 38%, which is somewhat expected given combination immunotherapy. We talked about nivolumab and ipilimumab before, which, of course, gives even higher rates of immune-related adverse events, with the most common toxicities being anemia, lipase elevations, rash, ALC decrease; albeit, quite manageable.

Dr. Diwakar Davar: So, what about the objective response rate? Can you contextualize the efficacy? And as you do that, maybe we'll think about what you'd expect in the context of, say, gastric cancer, especially in patients who've never really had a prior checkpoint inhibitor before. What do you think about the ORR? What do you think about the relative efficacy of this combination?

Dr. Jason Luke: Well, so, in the study, they described overall response rate in the 36 patients as 36% and described immediate progression for survival of about 6.5 months. And so that was among patients who were treatment naive. And in second-line patients, they actually described an even higher response rate, although it was only 11 patients, but they're at 64%. And so, I think those data look to be somewhat interesting. When I was actually scrutinizing the actual data presented, it was of some interest to note that the quality of responses seemed to be about as good on the lower dose of LM-108, so 3 milligrams per kilogram as compared to 10 milligrams per kilogram. I think there's definitely more to learn here to try to optimize the dose and to fully understand what the overall efficacy of this treatment combination would be.

I would emphasize that in this disease, I think novel treatment strategies are certainly warranted. While anti PD-1 with chemotherapy has moved the needle in terms of standard of care treatment, it's really only a minor subset of patients who derive durable long-term benefit like we normally associate with immune checkpoint blockade. I think these are preliminary data. They're very intriguing.

You alluded to earlier that this population of patients was an Asian data set, and it is well known that the efficacy of chemotherapy and immunotherapy does appear to be somewhat enhanced in Asian populations, and that goes to distributions of metastasis and tumor microenvironment effects, etc. Very difficult to try to tease any of that out in this abstract, other than to look at these data and suggest that this is pretty interesting, both from a novel therapeutic approach, we talked about the Tregs consideration, but also straight up on the efficacy because I think if these data could hold up in a larger number of patients, and particularly in a western population of patients, I think it would be very intriguing.

Dr. Diwakar Davar: Certainly, ASCO 2024 had a lot of interesting data, including data from targeted agents, the LAURA trial, ADCs. But just focusing on the immune therapy subset, we certainly saw a lot of great advances in patients who were treated with neoadjuvant as well as relapse refractory disease in the context of RP1 and then a couple of newer agents such as this petosemtamab as well as LM-108. And of course, we cannot forget to highlight the extended DMFS data from the pembro vaccine study from KEYNOTE-942.

Jason, as always, thank you for taking a little bit of time out of your extremely busy schedule to come and give us insights as to how these agents are impacting the landscape. We really value your input and so thank you very much.

Dr. Jason Luke: Thank you for the opportunity.

Dr. Diwakar Davar: And thank you to our listeners for your time today. You will find the links to all the abstracts that we discussed 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 podcasts. So, thank you.

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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