Study of anti-PD-1 antibody pembrolizumab and pegylated-interferon alfa-2b (Peg-IFN) for advanced melanoma.

e20018 Background: The anti-PD-1 antibody pembrolizumab provides durable clinical benefits to 30-40% of patents with advanced melanoma.A number of murine and human studies suggest that pre-existing CD8+ T cell responses to melanoma and presence of an IFN-a gene signature may correlate with clinical response to immunotherapies, including PD-1 blockade. In this trial, we have tested the hypothesis that Peg-IFN stimulates T cell response to melanoma, increasing clinical response to PD-1 blockade. Methods: This safety and dose-seeking study of combination pembrolizumab and Peg-IFN for patients ( ≥ 18) with recurrent inoperable AJCC stage III and metastatic stage IV melanoma. Pembrolizumab is given 2 mg/kg q3 weeks for 2 years while Peg-IFN is given SC at 3 dose levels (1, 2 and 3 mcg/kg) to identify the recommended phase 2 dose (RP2D) prior to dose expansion up to 32 patients. Results: . Twelve patients have been enrolled in this trial (4 patients at each dose level). Previous treatments include adjuvant IFN,...