Inclusion Criteria:  Disease Criteria - Part 1A and 1C- Any histologically or cytologically confirmed solid tumor malignancy that is locally advanced or metastatic and has failed standard therapy, or standard therapy is not curative or available; Part 1B - Any histologically or cytologically confirmed solid tumor malignancy for which anti-PD-1 or anti-PD-L1 treatment is approved and has progressed on or after prior anti-PD-1 or anti-PD-L1 therapy. Part 2- histologically or cytologically confirmed unresectable or metastatic melanoma that has not been treated with prior anti-PD-1 or anti-PD-L1 therapy ECOG performance status of 0 or 1 Adequate organ function Part 2 only: measurable disease per iRECIST  Exclusion Criteria:  Received prior treatment with anti-CTL-4 therapy Received prior immune-checkpoint therapy and experienced Grade 3 or greater toxicity lasting greater than 6 weeks Received prior systemic anticancer therapy within 4 weeks prior to study treatment Received prior radiotherapy within 2 weeks prior to study treatment Has a diagnosis of immunodeficiency Has known malignancy (other than disease under study) that is progressing or has required active treatment within the past 3 years Has an active autoimmune disease that has required systemic treatment in past 2 years, including the use of disease modifying agents, corticosteroids or immunosuppressive drugs Has an active infection requiring systemic therapy within 4 weeks prior to study treatment Has a history of severe hypersensitivity reaction (≥ Grade 3) to any study intervention and/or any of its excipients Has a known psychiatric or substance abuse disorder that would interfere with the participant's ability to cooperate with the requirements of the study Part 2 only: has ocular melanoma Part 2 only: has received prior anti-PD-1/L-1 therapy