A Study of Fianlimab, Cemiplimab, and Ipilimumab in People With Melanoma

Inclusion Criteria: * Age ≥ 18 years at the time of informed consent * Patient/legal authorized representative (LAR) must be able to provide informed consent. * Patient must have a histologically confirmed diagnosis of locally advanced unresectable stage III/IV or metastatic stage IV cutaneous or mucosal melanoma that has progressed on PD-1/PD-L1 therapy: o For Cohort A, the patient's melanoma must have progressed on prior PD-1 monotherapy * For Cohort B, the patient's melanoma must have progressed on prior combination PD-1 + LAG-3 blockade * Note: Intervening lines of targeted therapy, chemotherapy, bispecific (e.g. IMCgp100) and cell-based therapies are permitted between last ICI-based therapy and the start of study therapy * Note: For cohort A, peptide and mRNA vaccines may have been combined with PD-1 monotherapy as long as no other checkpoint inhibitors were concomitantly administered. For cohort B, peptide and mRNA vaccines may have been combined with combined PD-1 + LAG-3 blockade as long as no other checkpoint inhibitors were concomitantly administered Note: Prior PD-1 monotherapy (Cohort A) or PD-1 and LAG-3 blockade (Cohort B) may have been given in the neoadjuvant or adjuvant setting as long as progression is documented within 3 months of the final dose neoadjuvant/adjuvant therapy * Patients must have measurable disease as defined by RECIST v1.1 o Note: Lesions previously injected with Talimogene laherparepvec or other local therapies may not be selected…