Phase 1 study of pembrolizumab (pembro; MK-3475) plus ipilimumab (IPI) as second-line therapy for advanced non-small cell lung cancer (NSCLC): KEYNOTE-021 cohort D.

8011 Background: Pembro is a potent anti–PD-1 monoclonal antibody. IPI, an anti–CTLA-4 antibody, has shown activity in advanced NSCLC. In melanoma, combined anti–PD-1 and anti–CTLA-4 treatment has shown robust efficacy and manageable toxicity. We report interim results from a phase 1 study evaluating pembro + IPI in patients (pts) with recurrent NSCLC. Methods: Pts with stage IIIB/IV NSCLC that recurred after ≤ 2 prior regimens received pembro + IPI every 3 wk for 4 cycles followed by maintenance pembro. Based on emerging data from the nivolumab + IPI advanced NSCLC study, doses were reduced from 10 mg/kg to 2 mg/kg for pembro and from 3 mg/kg to 1 mg/kg for IPI). Primary end point was safety and incidence of dose-limiting toxicities (DLTs) in the first 3 wk of dosing. Response was assessed every 6 wk per RECIST 1.1 by investigator review. Results: As of Dec 2014,17 pts were enrolled: 3 at pembro 10 mg/kg + IPI 3 mg/kg, 3 at pembro 10 mg/kg + IPI 1 mg/kg, and 11 at pembro 2 mg/kg + IPI 1 mg/kg. No DLTs or...