Melanoma – Differences in overall survival (OS) between EU and USA

NIVO+IPI (Nivolumab + Ipilimumab) and NIVO alone significantly improved PFS and OS vs. IPI alone in the CheckMate 067 study. Now post-hoc analyses by regions were performed to evaluate potential differences between patients treated in the EU and those treated in the USA. Baseline patient characteristics, safety and efficacy were evaluated. The minimum follow-up was 28 months.

EU patients were more likely to have M1c disease than USA pts (60 % vs. 53 %), and more likely to have BRAF wild type (WT) tumors (69 % vs 59 %). The only significant interaction between NIVO+IPI and NIVO after adjusting for baseline factors was by region. Adjusted hazard ratios (HRs) for OS in the NIVO+IPI vs IPI groups were 0.90 (0.66-1.23) for the EU and 0.53 (0.29-0.98) for the USA. Across all arms, 2-year OS-rates were lower in the EU vs USA pts, particularly for pts with BRAF WT tumors. In patients with BRAF mutant tumors, similar OS outcomes were observed between regions.
Treatment exposure, safety, management of adverse events, and use of subsequent therapies did not differ substantially between the two regions. Objective response rates and progression-free survival were also similar between the two regions.