JCO Article Insights: Nivolumab + Relatl...

In this JCO Article Insights episode, Rohit Singh provides a summary on "First-Line Nivolumab Plus Relatlimab Versus Nivolumab Plus Ipilimumab in Advanced Melanoma: An Indirect Treatment Comparison Using RELATIVITY-047 and CheckMate 067 Trial Data", by Long et al, published in the November issue of the Journal of Clinical Oncology. The article provides insights into the use of the two dual immune checkpoint inhibitor regimens in patients with untreated advanced melanoma.

TRANSCRIPT

Rohit Singh: Hello and welcome to JCO Article Insights. I'm your host Rohit Singh, Assistant Professor at the University of Vermont Cancer Center and today we'll be discussing the article “First-Line Nivolumab Plus Relatlimab Versus Nivolumab Plus Ipilimumab in Advanced Melanoma: An Indirect Treatment Comparison Using RELATIVITY-047 and CheckMate 067 Trials,” authored by Dr. Georgina Long from the Melanoma Institute of Australia and her colleagues. 

So as we know, nivolumab plus relatlimab and nivo plus ipi, I'm going to refer to as ipi-nivo moving forward, are dual immune checkpoint inhibitors regimens that are approved for treating patients with advanced melanoma based on the phase 2 and 3 RELATIVITY-047 and phase 3 CheckMate 067 trials respectively. Nivo plus relatlimab is the only dual PD-1 and LAG-3 inhibitor regimen approved for treating patients with advanced melanoma and relatlimab is the first in class human IgG4 LAG-3 blocking antibody. Ipi plus nivo is a dual PD-1 and CTLA-4 inhibitor regimen. 

So this paper basically is an indirect treatment comparison using a patient level database from these trials and this pretty much was conducted because of the absence of head to head trials looking at different regimens in advanced melanoma in first line setting. In this trial, the authors tried to compare these two trials. However, it's always hard to compare two different trials and we usually don't do cross trial comparisons. The problem is that the groups might be different to begin with. For example, one group might have younger patients, healthier patients, while the other might have older or sicker. These differences can make it hard to tell if the treatment caused improvement or if the groups were different to begin with. In this trial, researchers use inverse probability of treatment weighting to adjust the baseline differences between the two patient groups or between these two trials. Inverse probability of treatment weighting is a method used in research to help make a fair comparison between two groups when studying how a treatment intervention works. Basically, IPTW helps level the playing field between the two groups or like two trials for this paper. So, it calculates the likelihood of receiving a treatment. For each person, for each patient, researchers estimate the chance they would have gotten the treatment based on their characteristics like age, health, condition, their baseline staging, and based on that they create weights. People who are less likely to get the treatment but did are given more weight, and those who are very likely to get the treatment are given less weight. The same is done for the group that didn't get the treatment, and then they rebalance the groups. By applying these weights the group becomes more similar in their characteristics as if everyone had an equal chance of getting the treatment. This way, IPTW helps researchers focus on the effect of treatment itself and other differences between the groups. It's like adjusting the scales to make sure you are comparing apples to apples. 

The key outcomes the authors are looking at in this one was progression free survivals, overall survival, confirmed objective response rate, melanoma specific survival, and treatment related adverse events. Looking at the results of this cross comparison trial, first looking at the PFS or progression free survival, both regimens ipi plus nivo and nivo plus relatlimab, showed similar PFS. At 36 months, PFS was 36% in nivo-relatlimab versus 39% in the ipi-nivo regimen with a hazard ratio of 1.08 indicating no significant differences. Looking at the overall survival at 36 months, overall survival was 57% in both the treatment regimens with a hazard ratio of 0.14, again, indicating no significant differences. Now looking at another confirmed objective response rate, confirmed objective rates were similar between both treatment regimens after weighting, 48% versus 50% with an odds ratio of 0.91 suggesting comparable response rates between the two regimens. Looking at melanoma specific survival at 36 months it was 65% versus 62%. Both treatments had similar melanoma specific survival with a hazard ratio 0.86. 

An interesting thing in these results was subgroup analysis. Subgroups showed larger numerical differences in efficacy which favored ipi-nivo over nivo-relatlimab that included acral melanoma with a hazard ratio of 1.42 and OS with a hazard ratio of 1.72 in favor of ipi-nivo. Similarly for BRAF mutant melanoma, it showed a confirmed objective response rate with odds ratio 1.54 and same applied to mucosal melanoma with odds ratio of 1.59 and patients who have high LDH more than two times upper level limit. Looking at the safety and adverse side effects, nivolumab plus relatlimab had fewer grade 3 or 4 treatment related adverse effect which is 23% versus 61% and fewer any grade treatment related adverse events leading to discontinuation which was 17% versus 41%, which means 41% of the patients in the ipi-nivo arm lead to discontinuation. However, I would like to add to that that ipi-nivo was conducted much earlier and at that time we were still kind of assessing and trying to understand the immunity adverse effects, how to manage them, which probably could have made discontinuation more common compared to a nivo-relatlimab trial. By that time we definitely had much more experience dealing with immunity adverse effects.A couple of things mentionable in this, notable rates of hepatic and GI grade 3 or 4 treatment adverse events were lower in nivo plus relatlimab than with ipi-nivo, although the onset of any grade endocrine GI hepatic or skin related treatment related adverse events occurred most frequently in both treatment arms and in less than three months from randomization. 

So looking at all this data and looking at all this, it definitely seems like both the trials are very comparable in terms of efficacy, though nivo plus relatlimab seems to have a better safety profile. This trial does have some strengths. It does use the patient level data from two large well conducted trials allowing for a robust comparison and inverse weighting which would definitely better help balance baseline characteristics, enhancing the reliability of the results, and it does lead to comprehensive assessment of both efficacy and safety outcomes, and provides a holistic view of the treatments. Given all this, definitely the fact that it's a cross comparison trial which leads to a big limitation, as I already mentioned, like definitely two trials, it's hard to compare two trials which can have its own inherited biases. So it has some differences in trial design, conduct and follow up times. Small size subgroup analysis definitely limits the ability to draw definite conclusions from those groups. There's definitely some inherent uncertainty with direct head to head cross comparison trials. 

Looking at the future direction I would take from this trial, if we can have a direct head to head trial because both of the treatments are proven first line setting, it will be comparing these two regimen that can definitely provide more definite evidence and further research is needed to explore the efficacy of these regimens in specific subgroups. As I mentioned in this, some subgroups showed increased benefit in the ipi-nivo regimen, however, they were very small sample size so we need more research exploring those subgroups. One other part in both these trials, patients with active brain mets were excluded. However, there's a phase 2 trial looking at ipi-nivo in active brain mets patients. So I think assessing patients with active brain mets moving forward is also a crucial part looking at, because often, patients with advanced melanoma develop brain mets. It does lead to some unanswered questions like long term survival and quality of life. How do these regimens compare in terms of long term survival and quality of life? While the study provides data on PFS and OS, long term survival and quality of life metrics are essential for understanding the full impact of these treatments. Optimal sequencing strategies: what are the optimal sequence strategies for these patients who progress on one regimen? There is data suggesting that patients may respond to alternative regimens after progression, but more research is needed to establish the best treatment sequence. And real world performance: how do these treatments perform in real world settings outside of clinical trials? Real world data can provide insight into the effectiveness and safety of these regimens in a broader patient population. 

So, in summary, nivo plus relatlimab offers similar efficacy to nivolumab plus ipilimumab but a significantly improved safety profile, making it the potentially preferable option for patients with untreated advanced melanoma. However, results should be interpreted with caution due to limitations of cross trial analysis for certain subgroups like acral melanoma, mucosal melanoma, BRAF mutant melanoma, and patients with high LDH more than two times off upper normal limit. The trial showed that there's a trend definitely with ipi-nivo may be more beneficial. Also, today data on the use of nivolumab plus relatlimab in active brain mets has not been reported. Based on these existing data, ipi-nivo remains a standard immunotherapy for patients with active brain mets. Further research, including direct head to head trials is needed to confirm these findings and explore optimal treatment strategies. 

Thank you for tuning into today's episode. We hope this detailed summary of the study comparing Nivolumab Plus Relatlimab and Nivolumab Plus Ipilimumab in advanced melanoma has been informative. This is Rohit Singh. Thank you again for listening to JCO Article Insights. Don't forget to give us a rating or review and be sure to subscribe so you never miss an episode. You can find all ASCO shows at asco.org/podcasts.

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