Interim analysis of a phase Ib study of cobimetinib plus atezolizumab in patients with advanced BRAFV600 wild type melanoma progressing on prior anti-PD-L1 therapy

Abstract

Background Treatment options for patients (pts) with BRAFV600 wild type advanced melanoma following failure on anti–programmed death receptor 1 (aPD-1) therapy are limited. Melanoma is strongly driven by MAPK signaling. The MEK inhibitor cobimetinib inhibits MAPK signaling and increases immune cell infiltrate in the tumor, providing a strong rationale for combining cobimetinib with the anti–PD ligand-1 (PD-L1) antibody atezolizumab. Methods This multisite, phase Ib study enrolled pts with BRAFV600 wild type advanced melanoma with disease progression on or after aPD-1 therapy (≤12 weeks before study entry) to 2 cohorts. In cohort A, pts received oral cobimetinib 60mg (once daily, 21 days on, ..