Pemetrexed and Cisplatin for Advanced Non-squamous Non-small Cell Lung Cancer in Japanese Patients: Phase II Study

Background: Although pemetrexed/cisplatin (P-C) is a standard treatment for advanced non-squamous non-small cell lung cancer (Nsq-NSCLC), neither its efficacy nor the effects of potential differences between driver mutations, such as the anaplastic lymphoma kinase (ALK) translocation and epidermal growth factor receptor (EGFR) mutations, have been thoroughly examined. Patients and Methods: A single-arm phase II study of P-C was conducted in Japanese patients with chemo-naive advanced Nsq-NSCLC. Patients received four cycles of pemetrexed (500 mg/m(2)) combined with cisplatin (75 mg/m(2)) on day 1 every three weeks. The primary end-point was the response rate (RR) and the secondary end-points were toxicity, progression-free survival (PFS), and overall survival (OS). Results: A total of 50 patients were analyzed (males, 68%; adenocarcinoma, 80%). The RR was 44.0%. The median PFS and OS were 4.3 months and 22.2 months, respectively. Toxicities were mild, and no new toxicity profiles were identified. Among the 39 out of 50 samples, six (15.4%) presented ALK translocation and nine (23.1%) presented EGFR mutations; of the remaining patients, 24 (61.5%) were wild-type for both ALK and EGFR. Objective response was observed in two out of six patients with ALK translocations, six out of nine with EGFR mutations, and in 11 (45.8%) wild-type patients. Conclusion: The combination of pemetrexed and cisplatin was effective and safe in Japanese patients with Nsq-NSCLC. We did not observe obvious differences in the efficacy of P-C between patients with ALK translocation or EGFR mutation and those with wild-type genotype.