Inclusion Criteria:

          1. Age ≥ 18 years

          2. Written informed consent must be obtained from all patients prior to any study
             procedures

          3. Patients with advanced non-uveal melanoma defined as unresectable stage III or
             metastatic stage IV disease. Patients with acral or mucosal melanoma are acceptable.

          4. Phase 1b Arm 4 and Phase II: Patients with disease progression following initiation of
             treatment with an approved PD-1 inhibitor. No prior cytotoxic therapy in the advanced
             setting is permitted. Patients with BRAF mutations must be refractory to approved
             BRAF-based therapy. CTLA-4-inhibition therapy is acceptable as a prior line of therapy
             or in combination with anti-PD-1 therapy.

          5. HLA-A*0201 positive by Central Assay

          6. Eastern Cooperative Oncology Group (ECOG) Performance Status of 0 or 1

          7. Phase II cohorts only: patients must have measurable disease according to RECIST v.1.1
             criteria. Patients enrolled in Ph Ib cohorts must have evaluable disease

          8. Ongoing treatment with systemic steroids or other immunosuppressive therapies.

        Exclusion Criteria:

          1. Presence of untreated or symptomatic central nervous system metastases, or central
             nervous system metastases.

          2. History of severe hypersensitivity reactions to other mAbs

          3. History of treatment-related interstitial lung disease/pneumonitis

          4. Impaired baseline organ function as evaluated by out-of-range laboratory values.

          5. Clinically significant cardiac disease or impaired cardiac function.

          6. Active autoimmune disease or a documented history of autoimmune disease.

          7. Active infection requiring systemic antibiotic therapy. Patients requiring systemic
             antibiotics for infection must have completed therapy before Screening is initiated

          8. Known history of human immunodeficiency virus (HIV) infection. Testing for HIV status
             is not necessary unless clinically indicated or if required by local regulation

          9. Active hepatitis B virus (HBV) or hepatitis C virus (HCV) infection, currently
             requiring medical intervention, per institutional protocol. Testing for HBV or HCV
             status is not necessary unless clinically indicated or the patient has a history of
             HBV or HCV infection requiring treatment with currently an unknown status. History of
             treated hepatitis is not exclusionary

         10. Malignant disease, other than that being treated in this study. Pregnant or breast
             feeding.