Keynote-407 China Extension study: Pembrolizumab (pembro) plus chemotherapy in Chinese patients with metastatic squamous NSCLC

Abstract Background The primary analysis of OS and PFS in the randomized KEYNOTE-407 study, at median follow-up of 7.8 months, showed that pembro + carboplatin and paclitaxel/nab-paclitaxel (chemo) significantly improved OS (HR, 0.64 [95% CI, 0.49–0.85]; P  Methods The global and China extension studies were designed similarly. Pts from mainland China were randomized 1:1 to 35 cycles of pembro or placebo + 4 cycles of carboplatin and paclitaxel. Randomization was stratified by PD-L1 TPS (≥1%/ Results 125 pts from mainland China were randomized to pembro + chemo (n = 65) or placebo + chemo (n = 60). At data cutoff (May 9, 2019), median follow-up was 10.4 months (range, 0.6–22.6). 58% of pts in the control arm had crossed over on-study to pembro monotherapy. Pembro + chemo improved OS, PFS, ORR, and DOR vs placebo + chemo (Table). Grade 3 − 5 AEs occurred in 89% and 87% of pts in the pembro + chemo and placebo + chemo arms, respectively; immune-mediated AEs and infusion reactions (any grade) occurred in 29% and 10%. Table . LBA20 Pembro + Chemo n = 65 Placebo + Chemo n = 60 Median OS (95% CI), mo 17.3 (14.1–NR) 12.6 (9.6–NR) - HR (95% CI) 0.44 (0.24–0.81) Median PFS (95% CI), mo a 8.3 (6.2–10.3) 4.2 (4.0–4.4) - HR (95% CI) 0.32 (0.21–0.49) ORR, % (95% CI) a 78.5 (66.5–87.7) 41.7 (29.1–55.1) - Median DOR (range), mo 8.9 (1.7+ to 14.4+) 3.5 (2.4+ to 9.0+) “+” indicates no PD by the time of last disease assessment. a Assessed by RECIST v1.1 per blinded independent central review. NR, not reached. Conclusions Pembro + chemo improved OS, PFS, and ORR vs placebo + chemo, with a manageable safety profile, in pts from mainland China. These data are consistent with findings from the global study and support use of pembro + carboplatin and paclitaxel as a new standard of care for previously untreated metastatic squamous NSCLC in China. Clinical trial identification NCT02775435, NCT03875092. Editorial acknowledgement Vidya Ramachandran, PhD, of C4 MedSolutions, LLC (Yardley, PA, USA), a CHC Group company, and funded by Merck Sharp & Dohme Corp., a subsidiary of Merck & Co., Inc., Kenilworth, NJ, USA. Legal entity responsible for the study Merck Sharp & Dohme Corp., a subsidiary of Merck & Co., Inc., Kenilworth, NJ, USA. Funding Merck Sharp & Dohme Corp., a subsidiary of Merck & Co., Inc., Kenilworth, NJ, USA. Disclosure J. Ge: Full / Part-time employment: MSD China. H. Wang: Full / Part-time employment: MSD China. Y. Tian: Full / Part-time employment: MSD China. B. Piperdi: Shareholder / Stockholder / Stock options, Full / Part-time employment: Merck Sharp & Dohme Corp., a subsidiary of Merck & Co., Inc., Kenilworth, NJ, USA. L. Paz-Ares: Officer / Board of Directors: Genomica; Honoraria (self), Research grant / Funding (institution), Honoraria to self/spouse for scientific advice or as a speaker: AstraZeneca; Honoraria (self), Research grant / Funding (institution), Honoraria to self/spouse for scientific advice or as a speaker: Pfizer; Honoraria (self), Research grant / Funding (institution), Honoraria to self/spouse for scientific advice or as a speaker: BMS; Honoraria (self), Research grant / Funding (institution), Honoraria to self/spouse for scientific advice or as a speaker: MSD; Honoraria (self), Honoraria to self/spouse for scientific advice or as a speaker: Roche; Honoraria (self), Honoraria to self/spouse for scientific advice or as a speaker: Lilly; Honoraria (self), Honoraria to self/spouse for scientific advice or as a speaker: Boehringer Ingelheim; Honoraria (self), Honoraria to self/spouse for scientific advice or as a speaker: Novartis; Honoraria (self), Honoraria to self/spouse for scientific advice or as a speaker: Amgen; Honoraria (self), Honoraria to self/spouse for scientific advice or as a speaker: Merck; Honoraria (self), Honoraria to self/spouse for scientific advice or as a speaker: Sanofi; Honoraria (self), Honoraria to self/spouse for scientific advice or as a speaker: PharmaMar; Honoraria (self), Honoraria to self/spouse for scientific advice or as a speaker: Servier; Honoraria (self), Honoraria to self/spouse for scientific advice or as a speaker: Sysmex; Honoraria (self), Honoraria to self/spouse for scientific advice or as a speaker: Incyte; Honoraria (self), Honoraria to self/spouse for scientific advice or as a speaker: Ipsen; Honoraria (self), Honoraria to self/spouse for scientific advice or as a speaker: Adcap; Honoraria (self), Honoraria to self/spouse for scientific advice or as a speaker: Bayer; Honoraria (self), Honoraria to self/spouse for scientific advice or as a speaker: Blueprint Medicines; Honoraria (self), Honoraria to self/spouse for scientific advice or as a speaker: Celgene.