Efficacy and safety of cobimetinib (C) combined with vemurafenib (V) in patients (pts) with BRAFV600 mutation–positive metastatic melanoma: analysis from the 4-year extended follow-up of the phase 3 coBRIM study.

9522Background: The coBRIM study demonstrated that first-line C+V improved progression-free (PFS) and overall survival (OS) compared with placebo (P)+V in pts with BRAFV600-mutated advanced melanoma. We report updated survival outcomes and safety after extended follow-up. Methods: coBRIM was a double-blind, multicenter study in which 495 patients were randomized to receive C (60 mg once daily for 21 days followed by a 7-day rest period in each 28-day cycle; n = 247) or P (n = 248) in combination with V (960 mg twice daily). PFS and OS were primary and secondary endpoints, respectively. Results: At database closure, median follow-up duration for the overall intent-to-treat population was 18.6 months (range, 0.5–55.1 months); 176 pts (71%) in the C+V arm and 190 pts (77%) in the P+V arm had discontinued the study, with the most common reason being death (C+V = 148 pts [60%]; P+V = 162 pts [65%]). Median PFS among pts receiving C+V was 12.6 months (95% confidence interval [CI], 9.5–14.7 months) vs 7.2 months...