Efficacy and safety of pemetrexed/cisplatin versus gemcitabine/cisplatin as first-line treatment in Chinese patients with advanced nonsquamous non-small cell lung cancer

Abstract Objectives Retrospective subgroup analysis in JMDB study indicates that the between-arm differences in overall survival (OS) in the East Asian subgroup were consistent with those observed in the entire JMDB study population. This bridging study (JMIL) further evaluated the efficacy and safety of first-line pemetrexed/cisplatin (PC) versus gemcitabine/cisplatin (GC) in Chinese patients with nonsquamous non-small cell lung cancer (NSCLC). The primary endpoint of this local registration trial was designed to compare OS in the combined dataset, consisting of Chinese patients in JMIL and 1252 nonsquamous patients in JMDB. Materials and methods Chinese patients with stage IIIB/IV nonsquamous NSCLC were randomly assigned (1:1) to 6 cycles maximum (21 days/cycle) of pemetrexed 500mg/m 2 +cisplatin 75mg/m 2 (day 1), or gemcitabine 1250mg/m 2 (days 1 and 8)+cisplatin 75mg/m 2 (day 1). Results In JMIL, 256 Chinese patients were randomized (PC, n =126; GC, n =130). Patient baseline characteristics were balanced between treatment arms. In the combined dataset, PC was superior to GC in prolonging OS, with adjusted hazard ratio (HR) of 0.87 (95% CI: 0.77–0.98, p =0.023) and median OS of 11.76 versus 10.94 months. In the JMIL-only population, no significant OS difference observed between treatment arms (adjusted HR=1.03 [95% CI: 0.77–1.39, p =0.822]; unadjusted HR=0.996 [95% CI: 0.74–1.33, p =0.980]), nor for other secondary efficacy endpoints. Significantly fewer patients in the PC arm experienced drug-related grade 3/4 toxicities, 54 (43.2%) versus 71 (55.9%) for GC ( p =0.045), with significantly lower rates of leukocytopenia, thrombocytopenia, and fatigue. Conclusion This study showed that in the combined population, OS of PC was superior to GC, while in the Chinese-only population, no significant difference was observed; a better safety and risk/benefit profile was found in the PC arm. A PC regimen should be considered as a standard of care in Chinese nonsquamous NSCLC patients in a first-line setting.