Day 5: Top Takeaways From ASCO25

Dr. John Sweetenham shares highlights from Day 5 of the 2025 ASCO Annual Meeting, including data from large trials in advanced malignant melanoma and mCSPC plus a new approach to first-line treatment for patients with multiple myeloma who are not transplant eligible. Transcript Hello, I'm Dr. John Sweetenham, the host of the ASCO Daily News Podcast, with my takeaways on selected abstracts from Day 5 of the 2025 ASCO Annual Meeting. My disclosures are available in the transcript of this episode. The selected abstracts from this final day of ASCO25 include important new data from large, randomized trials in patients with advanced malignant melanoma and patients with metastatic castration-sensitive prostate cancer, as well as a new approach to the first-line treatment of patients with multiple myeloma who are not transplant eligible. Starting with LBA9500, this study was conducted in patients with completely resected stage III or IV malignant melanoma and compared the combination of relatlimab plus nivolumab versus nivolumab alone in this population. The study, named the RELATIVITY-098 trial, was presented by Dr. Georgina Long from the University of Sydney, Australia. In her introduction to the study, Dr. Long explained that the current standard of care for adjuvant therapy of resected stage III/IV melanoma is with PD-1 monotherapy with nivolumab, but that about 50% of patients will suffer from a subsequent relapse. In the first-line setting in patients with advanced or unresectable melanoma, the combination of nivolumab with the LAG-3 inhibitor, relatlimab, has been previously shown to improve progression-free survival in the RELATIVITY-047 trial. The current study evaluated this same combination in the adjuvant setting. More than 1,000 patients from 24 countries were randomized to receive either nivolumab alone (546 patients) or the combination of nivolumab with relatlimab (547 patients). Both treatments were given for a maximum of 1 year or until progression of disease, unacceptable toxicity, withdrawal, or death. Various biomarker studies were also undertaken including LAG-3 and PD-1 expression on CD8-positive T cells. The primary endpoint of the study was relapse-free survival, and Dr. Long reported that this was the same in both arms of the study. For example, at 24 months, the relapse-free survival was 64% in the monotherapy arm compared with 62% in the combination arm. The hazard ratio was 1.01 and the P value was 0.928. Metastasis-free survival was also identical in both arms. No benefit was observed for the combination in any of the prespecified subgroups. No new toxicity signals emerged compared with the RELATIVITY-047 trial. Interestingly, the baseline surface expression of LAG-3 and co-expression of LAG-3 and PD-1 on CD8 T cells in the 098 adjuvant trial were lower than in the 047 advanced disease trial, perhaps explaining why the combination did not confer benefit over nivo alone in the adjuvant setting. This is an important result, demonstrating that results from one clinical setting cannot always be extrapolated to another. Although the combination has gained some use in the adjuvant setting, this study clearly demonstrates that more drug in this situation is no better and that monotherapy remains the current standard of care. Results from the AMPLITUDE trial for patients with metastatic castration-sensitive prostate cancer with alterations in homologous recombination repair (HRR) genes, in LBA5006, were presented today by Dr. Gerhardt Attard from University College London, UK. This international, multicenter study evaluated the combination of the selective PARP inhibitor, niraparib, in combination with abiraterone acetate and prednisone. The same combination has been previously shown to improve outcomes in castration-resistant metastatic prostate cancer harboring BRCA mutations in the MAGNITUDE study. The current trial included patients with castration-sensitive disease with HRR mutations including BR