First-line atezolizumab monotherapy in patients with advanced BRAFV600 wild-type melanoma.

Anti-programmed death-1 agents are an established option for advanced melanoma, but the anti-programmed death-ligand 1 (anti-PD-L1) antibody atezolizumab, an agent approved for the treatment of multiple solid tumors, was not previously evaluated. This phase 1b study cohort (NCT03178851; cohort C) evaluated first-line atezolizumab 1,200 mg every 3 weeks in adults with BRAFV600 wild-type, histologically confirmed, advanced or metastatic melanoma. The co-primary end points were confirmed objective response rate (ORR) per Response Evaluation Criteria in Solid Tumors v1.1 and disease control rate (DCR = complete response [CR] +partial response [PR] +stable disease [SD] at 16 weeks). Of 52 enrolled patients, most had lactate dehydrogenase levels lower than the upper limit of normal (77%) and PD-L1-positive tumors (55%). Investigator-assessed confirmed ORR was 35% (95% CI, 22%-49%) and included three CRs (6%) and 15 PRs (29%); DCR was 46%. Median investigator-assessed progression-free survival was 3.7 months (95% CI, 2.1-7.3). The most common any-grade adverse events were anemia (27%), headache (19%), hypertension (19%), constipation (17%), diarrhea (17%), hypothyroidism (17%), asthenia (15%), and pain in extremity (15%). First-line atezolizumab monotherapy is safe and tolerable and has antitumor activity in patients with BRAFV600 wild-type advanced or metastatic melanoma.