Peripheral T Cell Determinants of Response and Resistance to Pembrolizumab in Melanoma

Eligibility Criteria

• 1. Patients must have histologically confirmed locally advanced or metastatic melanoma and be starting on standard of care pembrolizumab monotherapy. Patients may have received any or no prior anti-cancer therapy without limitation.
• 2. Must have one or more sites of disease amenable to biopsy (tumor, skin, lymph node, pleural fluid, peritoneal fluid, cerebral spinal fluid (CSF)).
• 3. Have measurable disease based on Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1. Lesions situated in a previously irradiated area are considered measurable if progression has been demonstrated in such lesions.
• 4. Participants must be age 18 years or older on the day of signing informed consent.
• 5. Have the ability to provide written informed consent for the trial.
• 6. Be able and willing to comply with study procedures including provision of basic demographic information and medical history.
• 7. Be willing to receive periodic follow up phone calls to monitor health status and survival status.
• 1. Has received prior therapy with an anti-PD-1, anti-PD-L1, or anti PD L2 agent or with an agent directed to another stimulatory or co-inhibitory T-cell receptor (e.g., cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), OX 40, Cluster of Differentiation 137 (CD137)).
• 2. Has received prior systemic anti-cancer therapy including investigational agents within the prior 2 weeks.
• 3. Has a diagnosis of immunodeficiency or is receiving chronic systemic steroid therapy (in dosing exceeding 10 mg daily of prednisone equivalent) or any other form of immunosuppressive therapy within 7 days prior to the first dose of study drug.
• 4. Has a contraindication to tissue biopsy for minimally-invasive research-procedure
• 5. Contraindication to phlebotomy (up to 20 milliliters (mL)) per phlebotomy every three weeks).