A Study to Evaluate ABP 206 Compared With OPDIVO® (Nivolumab) in Subjects With Unresectable or Metastatic Melanoma

Key Inclusion Criteria: * At least 18 years of age. * Histologically confirmed unresectable or metastatic melanoma. * Subject has no prior systemic treatment for advanced disease. * Subject must have measurable disease according to Response Evaluation Criteria in Solid Tumors (RECIST version 1.1). * Tumor tissue from site of unresectable or metastatic melanoma must be available for biomarker analyses in order to be randomized. * Eastern Cooperative Oncology Group (ECOG) performance status (PS) 0 or 1. Key Exclusion Criteria: * Subject has had any prior systemic anti-cancer therapy for the treatment of advanced melanoma. * Known hypersensitivity to monoclonal antibodies or to any of the excipients of the study drug. * Subject has active central nervous system (CNS) metastases not previously treated. * Ocular melanoma. * Subject has active or known immune-mediated disorders. * Subject has had prior treatment with PD-1/PD-L1 and cytotoxic T lymphocyte- associated protein 4 inhibitors, or other antibodies targeting immune checkpoint pathways. * Subject has medical conditions requiring systemic immunosuppression with either corticosteroids or other immunosuppressive medications within 14 days of the first dose of investigational product. Other protocol-defined inclusion/exclusion criteria apply.