Five-year data extend the case for dual immune checkpoint blockade
A five-year analysis of the phase 2–3 RELATIVITY-047 trial has found that combining relatlimab with nivolumab continued to outperform nivolumab alone for people with metastatic or unresectable melanoma.
The peer-reviewed analysis, published in Nature Medicine, reports the longest follow-up yet from the pivotal study underlying approval of the combination. With a minimum follow-up of 57.3 months, researchers said the two-drug regimen showed continued clinically significant benefit across progression-free survival, overall survival and melanoma-specific survival.
Melanoma that has spread or cannot be removed surgically remains a difficult disease to treat. Immunotherapy has reshaped care by helping the immune system recognize and attack tumors, but not every patient responds and the durability of benefit is a central question. Long-term results matter because an early separation in trial outcomes may narrow with time; in this study, the researchers report that the survival curves remained separated.
How the study was conducted
RELATIVITY-047 was a double-blind, randomized study involving patients with metastatic or unresectable melanoma. Participants were assigned in a 1:1 ratio to receive either nivolumab 480 mg plus relatlimab 160 mg, or nivolumab 480 mg alone, administered intravenously every four weeks.
The combination group included 355 participants, while 359 received nivolumab alone. The trial’s primary endpoint was progression-free survival, assessed by blinded independent central review. Secondary endpoints included overall survival, response and safety. The newly reported analysis also included melanoma-specific survival and exploratory biomarker analyses.
Blinding and independent review are important features in oncology trials because they reduce the risk that treatment expectations influence assessments such as whether a patient’s disease has progressed. The five-year report therefore provides a more mature view of outcomes from the same trial rather than evidence from a separate comparison.
What the five-year results show
The reported hazard ratio for progression-free survival was 0.77 for the combination compared with nivolumab alone, with a 95% confidence interval of 0.65 to 0.92. For overall survival, the hazard ratio was 0.78, with a 95% confidence interval of 0.64 to 0.95. Melanoma-specific survival had a hazard ratio of 0.71, with a 95% confidence interval of 0.57 to 0.88.
Hazard ratios below 1 favor the combination in these comparisons. In practical terms, the results indicate a lower relative risk of the measured event over the follow-up period for patients receiving relatlimab plus nivolumab than for those receiving nivolumab alone. The confidence intervals reported by the authors did not cross 1 for these endpoints.
The authors characterize the analysis as showing the largest absolute differences to date in progression-free survival, overall survival and melanoma-specific survival. That distinction is significant: progression-free survival measures the time before disease progression or death, while overall survival measures death from any cause. Melanoma-specific survival focuses on deaths attributed to the cancer itself.
Safety and biomarker work remain part of the picture
Longer follow-up is also essential for evaluating safety in treatments that activate the immune system. The researchers reported that the safety profile remained consistent with earlier findings. The supplied study text does not provide detailed rates of adverse events, so the new report should not be read as establishing that the combination is free of additional treatment burden. Instead, it indicates that no change in the overall safety profile was highlighted in the five-year summary.
The publication also includes exploratory biomarker analyses. Biomarkers can potentially help explain why some tumors or patients benefit more from a therapy than others, but the report’s abstract does not provide enough detail to draw treatment-selection conclusions from those analyses. Their inclusion nevertheless signals that the trial is looking beyond the average result toward the biology underlying response.
Why the follow-up matters
The combination is already approved for advanced melanoma on the basis of RELATIVITY-047. The new data do not introduce a new treatment, but they add maturity to the evidence behind an existing option. For clinicians and patients weighing immunotherapy approaches, the persistence of benefit after at least 57.3 months of follow-up is a meaningful part of that evidence base.
Results from a controlled clinical trial should still be interpreted in the context of the studied population and regimen. The paper does not claim that every patient will benefit equally, nor does the supplied information establish which individuals should receive the treatment. But it does show that, in this randomized comparison, the advantage of relatlimab plus nivolumab over nivolumab alone was still evident at five years.
As melanoma treatment continues to evolve, durable outcomes and clearer biomarker evidence will be central to determining how combination immunotherapies are used. RELATIVITY-047 now offers a long-term benchmark: the addition of relatlimab to nivolumab was associated with sustained improvements in multiple survival measures, while the reported safety profile remained consistent with prior observations.
This article is based on reporting by Nature Medicine. Read the original article.
Originally published on nature.com
