Pembrolizumab and platinum-based chemotherapy as first-line therapy for advanced non small-cell lung cancer: Phase 1 cohorts from the KEYNOTE-021 study

Objectives: Platinum-based chemotherapy for advanced non small-cell lung cancer (NSCLC) has modest benefit overall, but has the potential to amplify immune responses. In cohorts A-C of the multicohort phase 1/2 study KEYNOTE-021 (Clinicaltrials.gov, NCT02039674), we evaluated combinations of platinum-doublet chemotherapy with the anti programmed death 1 monocloncal antibody pembrolizumab. Materials and methods: Patients with previously untreated, advanced NSCLC without EGFR/ALK aberrations were randomized to pembrolizumab 2 or 10 mg/kg Q3W plus carboplatin area under the serum concentration time curve (AUC) 6 mg/mL/min plus paclitaxel 200 mg/m(2) (cohort A, any histology), carboplatin AUC 6 mg/mL/min plus paclitaxel 200 mg/m(2) plus bevacizumab 15 mg/kg (cohort B, non-squamous), or carboplatin AUC 5 mg/mL/min plus pemetrexed 500 mg/m(2) (cohort C, non-squamous) for 4 cycles followed by maintenance pembrolizumab (cohort A), pembrolizumab plus bevacizumab (cohort B), or pembrolizumab plus pemetrexed (cohort C). Response was assessed by blinded independent central review. Results: Overall, 74 patients were randomized; median follow-up was 21.4, 16.4, and 17.4 months in cohorts A, B, and C, respectively. No dose-limiting toxicities occurred in any cohort at either pembrolizumab dose. Most frequent treatment-related adverse events (AEs) were alopecia, fatigue, and nausea. Treatment-related grade 3/4 AEs occurred in 40%, 42%, and 46% of patients in cohorts A, B, and C, respectively; AEs with possible immune etiology occurred in 24%, 50%, and 38% of patients, respectively. Objective response rates were 48%, 56%, and 75% in cohorts A, B, and C, respectively. Conclusion: Pembrolizumab in combination with carboplatin-paclitaxel and with pemetrexed-carboplatin yielded encouraging antitumor activity and toxicity consistent with known toxicities of platinum-based chemotherapy or pembrolizumab monotherapy.