Dr. Diwakar Davar and Dr. Jason Luke discuss novel agents in melanoma and other promising new data in the field of immunotherapy that were presented at the 2025 ASCO Annual Meeting.

TRANSCRIPT

Dr. Diwakar Davar: Hello. My name is Diwakar Davar, and I am welcoming you to the ASCO Daily News Podcast. 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. Today, I'm joined by my colleague and good friend, Dr. Jason Luke. Dr. Luke is a professor of medicine. He is also the associate director of clinical research and the director of the Phase 1 IDDC Program at the University of Pittsburgh's Hillman Cancer Center. He and I are going to be discussing some key advancements in melanoma and skin cancers that were presented at the 2025 ASCO Annual Meeting. Our full disclosures are available in the transcript of this episode. 

Jason, it is great to have you back on the podcast.

Dr. Jason Luke: Thanks again so much for the opportunity, and I'm really looking forward to it.

Dr. Diwakar Davar: Perfect. So we will go ahead and start talking a little bit about a couple of key abstracts in both the drug development immunotherapy space and the melanoma space. The first couple of abstracts, the first two, will cover melanoma.

So, the first is LBA9500, which was essentially the primary results of RELATIVITY-098. RELATIVITY-098 was a phase 3 trial that compared nivolumab plus relatlimab in a fixed-dose combination against nivolumab alone for the adjuvant treatment of resected high-risk disease. Jason, do you want to maybe give us a brief context of what this is?

Dr. Jason Luke: Yeah, it's great, thanks. So as almost all listeners, of course, will be aware, the use of anti–PD-1 immunotherapies really revolutionized melanoma oncology over the last 10 to 15 years. And it has become a standard of care in the adjuvant setting as well.

But to review, in patients with stage III melanoma, treatment can be targeted towards BRAF with BRAF and MEK combination therapy, where that's relevant, or anti–PD-1 with nivolumab or pembrolizumab are a standard of care. And more recently, we've had the development of neoadjuvant approaches for palpable stage III disease. And in that space, if patients present, based on two different studies, either pembrolizumab or nivolumab plus ipilimumab can be given prior to surgery for somewhere in the 6- to 9-week range. And so all of these therapies have improved time-to-event endpoints, such as relapse-free or event-free survival.

It's worth noting, however, that despite those advances, we've had a couple different trials now that have actually failed in this adjuvant setting, most high profile being the CheckMate-915 study, which looked at nivolumab plus ipilimumab and unfortunately was a negative study. So, with RELATIVITY-047, which was the trial of nivolumab plus relatlimab that showed an improvement in progression-free survival for metastatic disease, there's a lot of interest, and we've been awaiting these data for a long time for RELATIVITY-098, which, of course, is this adjuvant trial of LAG-3 blockade with relatlimab plus nivolumab.

Dr. Diwakar Davar: Great. So with that, let's briefly discuss the trial design and the results. So this was a randomized, phase 3, blinded study, so double-blinded, so neither the investigators knew what the patients were getting, nor did the patients know what they were getting.

The treatment investigational arm was nivolumab plus relatlimab in the fixed-dose combination. So that's the nivolumab standard fixed dose with relatlimab that was FDA approved in RELATIVITY-047. And the control arm was nivolumab by itself. The duration of treatment was 1 year. The patient population consisted of resected high-risk stage III or IV patients. The primary endpoint was investigator-assessed RFS. Stage and geography were the standard stratifying factors, and they were included, and most of the criteria were balanced across both arms.

What we know at this point is that the 2-year RFS rate was 64% and 62% in the nivolumab and nivolumab-combination arms, respectively. The 2-year DMFS rate was similarly equivalent: 76% with nivolumab monotherapy, 73% with the combination. And similar to what you had talked about with CheckMate 915, unfortunately, the addition of LAG-3 did not appear to improve the RFS or DMFS compared to control in this patient population. So, tell us a little bit about your take on this and what do you think might be the reasons why this trial was negative?

Dr. Jason Luke: It's really unfortunate that we have this negative phase 3 trial. There had been a lot of hope that the combination of nivolumab with relatlimab would be a better tolerated combination that increased the efficacy. So in the metastatic setting, we do have 047, the study that demonstrated nivolumab plus relatlimab, but now we have this negative trial in the adjuvant setting. And so as to why exactly, I think is a complicated scenario.

You know, when we look at the hazard ratios for relapse-free survival, the primary endpoint, as well as the secondary endpoints for distant metastasis-free survival, we see that the hazard ratio is approximately 1. So there's basically no difference. And that really suggests that relatlimab in this setting had no impact whatsoever on therapeutic outcomes in terms of efficacy.

Now, it's worth noting that there was a biomarker subanalysis that was presented in conjunction with these data that looked at some immunophenotyping, both from circulating T cells, CD8 T cells, as well as from the tumor microenvironment from patients who were treated, both in the previous metastatic trial, the RELATIVITY-047 study, and now in this adjuvant study in the RELATIVITY-098 study. And to briefly summarize those, what was identified was that T cells in advanced melanoma seemed to have higher expression levels of LAG-3 relative to T cells that are circulating in patients that are in the adjuvant setting. In addition to that, there was a suggestion that the magnitude of increase is greater in the advanced setting versus adjuvant. And the overall summary of this is that the suggested rationale for why this was a negative trial may have been that the target of LAG-3 is not expressed as highly in the adjuvant setting as it is in the metastatic setting.

And so while the data that were presented, I think, support this kind of an idea, I am a little bit cautious that this is actually the reason for why the trial was negative, however. I would say we're not really sure yet as to why the trial was negative, but the fact that the hazard ratios for the major endpoints were essentially 1 suggests that there was no impact whatsoever from relatlimab. And this really makes one wonder whether or not building on anti–PD-1 in the adjuvant setting is feasible because anti–PD-1 works so well. You would think that even if the levels of LAG-3 expression were slightly different, you would have seen a trend in one direction or another by adding a second drug, relatlimab, in this scenario.

So overall, I think it's an unfortunate circumstance that the trial is negative. Clearly there's going to be no role for relatlimab in the adjuvant setting. I think this really makes one wonder about the utility of LAG-3 blockade and how powerful it really can be. I think it's probably worth pointing out there's another adjuvan