Pembrolizumab (pembro; MK-3475) plus platinum doublet chemotherapy (PDC) as front-line therapy for advanced non-small cell lung cancer (NSCLC): KEYNOTE-021 Cohorts A and C.

8031 Background: As monotherapy, the anti–PD-1 antibody pembro has shown robust antitumor activity in advanced NSCLC patients (pts). KEYNOTE-021 evaluated the safety, tolerability, and clinical activity of pembro + PDC for treatment-naive advanced NSCLC. Methods: Pts with stage IIIB/IV NSCLC and no prior systemic therapy were randomized 1:1 to pembro 2 or 10 mg/kg Q3W plus carboplatin AUC 6 + paclitaxel 200 mg/m2 (cohort A; any histology) or carboplatin AUC 5 + pemetrexed 500 mg/m2 (cohort C; nonsquamous without EGFR sensitizing mutation or ALK translocation only). Pts received pembro + PDC for 4 cycles followed by pembro maintenance in A and pembro + pemetrexed in C. The dose-limiting toxicity (DLT) observation window was the first 3 wk after initial dosing. Key eligibility criteria included ECOG PS 0-1, measurable disease, and adequate tumor sample for PD-L1 assessment. Response was assessed every 6 wk until confirmed progression (RECIST v1.1, investigator review). Results: As of Dec 2014, 44 pts (20 in...