Neoadjuvant and Adjuvant Checkpoint Blockade

Inclusion Criteria: * Capable of giving written informed consent, which includes compliance with the requirements and restrictions listed in the consent form * Patients must have histologically or cytologically confirmed stage IIIB/C or stage IV oligometastatic melanoma; oligometastatic melanoma is defined as three or fewer areas of resectable disease excluding central nervous system and bone involvement; patients with cutaneous, mucosal, acral, ocular or unknown primary melanomas are eligible for enrollment; for patients with stage IV disease with distant lymph nodes (stage M1a), a maximum of three separate lymph node sites fit the definition of oligometastatic disease; resectable tumors are defined as having no significant vascular, neural or bony involvement; only cases where a complete surgical resection with tumor-free margins can safely be achieved are defined as resectable * Patients will have at least one melanoma deposit that can undergo serial biopsy (at least 2 time points) during the neoadjuvant phase of the protocol; patients must be willing to provide tumor samples at the time points specified in the Study Procedure Tables * All patients must undergo a baseline tumor biopsy; in Arms A and B, tumor biopsy for PD-L1 testing (PD-L1 positivity is determined by greater than or equal to 1% of cells staining in the membrane by immunohistochemistry) is required for stratification; PD-L1 status is not required for enrollment on Arm C; the 28-8 clone for PD-L1 testing is…