Real-world treatment patterns and outcomes of patients with advanced melanoma treated with nivolumab plus relatimab.

e21501 Background: Programmed death-1 (PD-1) receptor inhibitors significantly increase survival rates for advanced melanoma, yet first-line PD-1 inhibitor therapy shows limited overall response rates (32.6%) and progression-free survival (4.6 months). Relatimab (RELA) was recently approved for the treatment of metastatic and unresectable stage III to IV melanoma in combination with nivolumab (NIVO). RELATIVITY-047 showed an ORR of 43% as a first-line treatment while RELATIVITY 020 showed an ORR of 9-12% in patients progressed on anti-PD-1 therapy. Although clinical trials have demonstrated NIVO-RELA provides benefit for patients with advanced melanoma, little is known about real-world treatment patterns and outcomes. Methods: We performed a retrospective review of all patients with stage III and IV melanoma treated with NIVO-RELA as first-(1L) or second-line or beyond (2L+) therapy at Inova Schar Cancer Institute between September 2021 to September 2023. Primary endpoints were overall response rate (ORR), complete response (CR), partial response (PR), stable disease (SD), and progression of disease (PD) which were evaluated using the RECIST v1.1 criteria. The Kaplan–Meier method was used to generate overall survival (OS) and progression free survival (PFS) median values. Results: Eighty-eight patients were followed for an average of 6.5 months following NIVO-RELA initiation. For 1L treated patients, ORR was 58% (21% PR, 37% CR). Median PFS was 11 months (95% CI 3.1-11). For 2L+ treated patients, ORR was 33% (14% PR, 19% CR). Median PFS was 9.8 months (95% CI 4.7-17.2). Subgroup analyses observed significantly different ORR between patients previously treated with versus without anti-CTLA4 therapy (29% v 44%; p = 0.017), patients treated with NIVO-RELA more than vs within 6 months from their last other therapy (50% v 27%; p = 0.004), and among patients with stage III vs stage IV disease (67% v 30%; p = 0.031) (Table 1). Conclusions: These real-world results support the use of NIVO + RELA in patients with advanced melanoma and emphasize the impressive efficacy of the drug combination in the IL and 2L+ settings compared to RELATIVITY-020 and 047. PFS and OS for 1L and 2L+ therapy with NIVO + RELA in this study aligned with or superposed results from previous trials. Further analyses with increased sample sizes and longer follow-up is warranted. Table: see text