An observational study of drug utilization and associated outcomes among adult patients diagnosed with BRAF-mutant advanced melanoma treated with first-line anti-PD-1 monotherapies or BRAF/MEK inhibitors in a community-based oncology setting.

INTRODUCTION Anti-PD-1 monotherapies (aPD-1) and BRAF/MEK inhibitors (BRAF/MEKi) changed the BRAF-mutant advanced melanoma treatment landscape. This study aimed to improve the understanding of real-world treatment patterns and optimal treatment sequence. METHODS This was a retrospective study of BRAF-mutant advanced melanoma patients who initiated 1L aPD-1 or BRAF/MEKi in the US Oncology Network between 1 January 2014 and 31 December 2017, followed through 31 December 2018. Patient and treatment characteristics were assessed descriptively, with Kaplan-Meier methods used for time-to-event endpoints. As the primary analysis, overall survival (OS) and physician-assessed progression-free survival (rwPFS) were evaluated with Cox proportional hazard regression models and propensity score matching (n = 49). RESULTS A total of 224 patients were included (median age 61 years, 62.9% male, 89.7% white): 36.2% received aPD-1 and 63.8% BRAF/MEKi. Median OS and rwPFS were longer among aPD-1 vs BRAF/MEKi patients (OS: not reached vs 13.9 months, log-rank P = .0169; rwPFS: 7.6 vs 6.5 months, log-rank P = .0144). Receipt of aPD-1 was associated with improved OS (HR = 0.602 vs BRAF/MEKi [95%CI 0.382-0.949]; P = .0287). Among patients without an event within 6 months of 1L initiation, receipt of aPD-1 was associated with a decreased risk of progression or death from 6 months onwards (HR = 0.228 [95%CI 0.106-0.493]; P = .0002). This association was not observed among patients within 6 months of 1L initiation (HR = 1.146; 95% CI 0.755-1.738). Results from the propensity score-matched pairs were consistent with these trends. CONCLUSION These results suggest a clinical benefit of 1L aPD-1 compared to BRAF/MEKi after 6 months of treatment for BRAF-mutant advanced melanoma. Future research should explore factors associated with early progression and their relationship with clinical outcomes.