Safety and efficacy of adjuvant anti-PD1 therapy (nivolumab) in combination with vaccine in resected high-risk metastatic melanoma.

9056^ Background: Nivolumab (BMS-936558), a fully human monoclonal antibody targeting the programmed death-1 (PD-1) receptor, has demonstrated clinical activity in advanced metastatic melanoma patients (pts). In this phase I study, the safety and activity of nivolumab plus a multipeptide vaccine was investigated as adjuvant therapy in resected stage IIIC and IV melanoma pts. Methods: HLA-A*0201 positive pts with HMB-45, NY-ESO-1, and/or MART-1 positive tumors received nivolumab (1mg/kg, 3mg/kg, or 10mg/kg IV) with a multipeptide vaccine (gp100, MART-1, NY-ESO-1, Montanide ISA 51 VG) every 2 weeks for 12 doses followed by nivolumab maintenance every 3 months (8 doses) or until disease recurrence. The primary objective was safety and determination of maximum tolerated dose (MTD). Secondary objectives were immunologic response and relapse free survival. Results: 33 pts were enrolled: 12 pts at 1mg/kg, 10 pts at 3mg/kg, and 11 pts at 10mg/kg nivolumab. Median age was 47 yrs; 55% male and 52% M1c disease (2 II...