NCT02908672 2025-07-20A Study of Atezolizumab Plus Cobimetinib and Vemurafenib Versus Placebo Plus Cobimetinib and Vemurafenib in Previously Untreated BRAFv600 Mutation-Positive Patients With Metastatic or Unresectable Locally Advanced MelanomaHoffmann-La RochePhase 3 Completed514 enrolled 25 charts 2 FDA