IMspire170 was an international, randomized, open-label, phase 3 study.Patients were randomized 1:1 to receive cobimetinib (60 mg, days 1-21) plus anti-programmed death-ligand 1 atezolizumab (840 mg every 2 weeks) in 28-day cycles or anti-programmed death-1 pembrolizumab (200 mg every 3 weeks)...In exploratory biomarker analyses, higher tumor mutational burden was associated with improved clinical outcomes in both treatment arms.