Dr. Vamsi Velcheti and Dr. Nate Pennell discuss novel treatment approaches in small cell and non-small cell lung cancer that were featured at the 2025 ASCO Annual Meeting.

TRANSCRIPT

Dr. Vamsi Velcheti: Hello, I'm Dr. Vamsi Velcheti, your guest host of the ASCO Daily News Podcast. I'm a professor of medicine and chief of hematology and oncology at the Mayo Clinic in Jacksonville, Florida.

The 2025 ASCO Annual Meeting featured some exciting advancements in small cell lung cancer, targeted therapies for non-small cell lung cancer, and other novel [treatment] approaches. Today, I'm delighted to be joined by Dr. Nate Pennell to discuss some of the key abstracts that are advancing the lung cancer field.

Dr. Pennell is the co-director of the Cleveland Clinic Lung Cancer Program and also the vice chair of clinical research at the Taussig Cancer Institute. Our full disclosures are available in the transcript of this episode.

Nate, it's great to have you back on the podcast. Thanks so much for being here.

Dr. Nate Pennell: Thanks, Vamsi. Always a pleasure.

Dr. Vamsi Velcheti: Let's get started, and I think the first abstract that really caught my attention was Abstract 8516, "The Randomized Trial of Relevance of Time of Day of Immunotherapy for Progression-Free and Overall Survival in Patients With Non-Small Cell Lung Cancer." What are your thoughts about this, Nate?

Dr. Nate Pennell: I agree. I thought this was one of the most discussed abstracts, certainly in the lung cancer session, but I think even outside of lung cancer, it got some discussion.

So, just to put this in perspective, there have been a number of publications that have all been remarkably consistent, and not just in lung cancer but across multiple cancer types, that immunotherapy, immune checkpoint inhibitors, are commonly used. And all of them have suggested, when looking at retrospective cohorts, that patients who receive immune checkpoint inhibitors earlier in the day – so in the morning or before the early afternoon – for whatever reason, appear to have better outcomes than those who get it later in the day, and this has been repeated. And I think many people just sort of assumed that this was some sort of strange association and that there was something fundamentally different from a prognostic standpoint in people who came in in the morning to get their treatment versus those who came later in the afternoon, and that was probably the explanation.

The authors of this randomized trial actually decided to test this concept. And so, about 210 patients with previously untreated advanced non-small cell lung cancer were randomly assigned to get chemo and immune checkpoint inhibitor – either pembrolizumab or sintilimab – and half of them were randomly assigned to get the treatment before 3 PM in the afternoon, and half of them were assigned to get it after 3 PM in the afternoon. And it almost completely recapitulated what was seen in the retrospective cohorts. So, the median progression-free survival in those who got earlier treatment was 13.2 months versus only 6.5 months in those who got it later in the day. So, really enormous difference with a hazard ratio of 0.43, which was statistically significant.

And perhaps even more striking, the median overall survival was not reached in the early group versus 17.8 months in the late group with a hazard ratio of 0.43, also highly statistically significant. Even the response rate was 20% higher in the early patients; 75% response rate compared to 56% in the late-time-of-day patients. So very consistent across all measures of efficacy with pretty good matched characteristics across the different groups.

And so, I have to tell you, I don't know what to make of this. I certainly was a skeptic about the retrospective series, but now we have a prospective randomized trial that shows essentially the same thing. So, maybe there is a difference between getting treated in the morning, although I have yet to hear someone give a very good mechanistic explanation as to why this would be. What were your thoughts on this?

Dr. Vamsi Velcheti: It's indeed fascinating, Nate, and I actually think this was a very interesting abstract. Really, I was caught off guard looking at the data. I mean, if it were a drug, we would be so excited, right? I mean, with those kind of survival benefits. I don't know. I think circadian rhythm probably has something to do with it, like different cytokine profiles at the time of administration. I mean, who knows? But I think it's a randomized trial, and I think I would expect to see a mad rush for treatment appointments early in the morning given this, and at least I want my patients to come in first thing in the morning. It'll be interesting to see.

Dr. Nate Pennell: It's important to point out that in this study, everyone got chemo and immunotherapy. And, at least in our cancer center, most patients who are getting platinum-doublet chemotherapy and immunotherapy actually do get treated earlier in the day already, just because of the length of the infusion appointment that's needed. So it really is oftentimes people getting single-agent immunotherapy who are often getting the later, shorter visits.

But if you have a choice, I think it would be very reasonable to have people treated earlier in the day. And I do think most of the impressions that I got from people about this is that they would like to see it reproduced but certainly well worth further investigation. And I personally would like to see more investigation into what the rationale would be for this because I still can't quite figure out, yes, if you got it at, say, you know, 5 PM, that's later in the day and I can understand that maybe your immune system is somewhat less receptive at that point than it would be in the morning. But because these checkpoint inhibitors have such long half-lives, it's still in your system the next morning when your immune system is supposedly more receptive. So I don't quite understand why that would be the case.

Well, let's move on to the next study. I would like to hear your thoughts on Abstract 8515, "Plasma-Guided, Adaptive First-Line Chemoimmunotherapy for Non-Small Cell Lung Cancer."

Dr. Vamsi Velcheti: Yeah, this was another abstract that seems to be really interesting in my opinion. I think there's kind of a lot of emphasis lately on ctDNA and MRD-based assays to monitor disease. In the lung cancer space, we haven't had a lot of clinical trials looking at this prospectively, and this was one of those pilot studies where they looked at circulating free DNA (cfDNA)-based response-adaptive strategy for frontline patients who are PD-L1 positive. So, patients started with pembrolizumab monotherapy, and based on plasma molecular response after 2 cycles, those patients without response received early treatment intensification with a platinum doublet. So the approach essentially was to reduce the chemotherapy exposure in patients who respond to immunotherapy. And only about 17.5% of the patients on the trial received chemotherapy based on lack of molecular response.

So, in this trial, what they found was patients with the cfDNA response had a markedly improved PFS of 16.4 months versus 4.8 months. So essentially, like, this is a really nice study to set a foundation on which we have to do larger studies to incorporate molecular markers trying to look at cfDNA response to inform treatment strategy, either escalation or de-escalation strategies. So, I thought it was a very interesting study.

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