Phase I trial of extended-dose anti-PD-1 antibody BMS-936558 with a multipeptide vaccine for previously treated stage IV melanoma.

8582 Background: BMS-936558, a fully human IgG4 anti-PD-1 antibody, has shown clinical activity in melanoma and renal cancer. Methods: 30 HLA A*0201 positive patients with unresectable, previously treated stage IV melanoma received MART-1/gp100/NY-ESO-1 peptides with adjuvant Montanide ISA 51 injected subcutaneously with BMS-936558 at 1, 3 or 10 mg/kg intravenously every 2 weeks for 24 weeks, followed by BMS-936558 alone every 3 months. No patient had prior ipilimumab. Endpoints were toxicity, correlative studies of immunity measured by ELISPOT and T-cell phenotype assays, and response by RECIST. Results: Median age was 62, with 14 men and 16 women. 73% of patients had M1c disease. One patient had dose limiting optic neuritis; one patient had dose limiting grade 3 interstitial pneumonitis. Of 10 patients at 1 mg/kg, 2 had confirmed partial responses (PR), both one year from initiation of study. 13 patients were treated at the 3 mg/kg cohort; 3 patients did not complete more than 3 doses secondary to progr...