Purpose: To evaluate the efficacy of pemetrexed plus cisplatin versus vinorelbine plus cisplatin as postoperative adjuvant chemotherapy in patients with pathologic stage II-IIIA nonsquamous non-small-cell lung cancer (NSCLC).
Patients and methods: We performed a randomized, open-label, phase III study at 50 institutions within 7 clinical study groups in Japan. Patients with completely resected pathologic stage II-IIIA (TNM 7th edition) nonsquamous NSCLC were randomly assigned to receive either pemetrexed (500 mg/m2, day 1) plus cisplatin (75 mg/m2, day 1) or vinorelbine (25 mg/m2, days 1 and 8) plus cisplatin (80 mg/m2, day 1) with stratification by sex, age, pathologic stage, EGFR mutation, and institution. These treatments were planned to be given every 3 weeks for 4 cycles. The primary end point was recurrence-free survival in the modified intent-to-treat population, excluding ineligible patients.
Result: Between March 2012 and August 2016, 804 patients were enrolled (402 assigned to vinorelbine plus cisplatin and 402 assigned to pemetrexed plus cisplatin). Of 784 eligible patients, 410 (52%) had stage IIIA disease and 192 (24%) had EGFR-sensitive mutations. At a median follow-up of 45.2 months, median recurrence-free survival was 37.3 months for vinorelbine plus cisplatin and 38.9 months for pemetrexed plus cisplatin, with a hazard ratio of 0.98 (95% CI, 0.81 to 1.20; 1-sided P = .474). Grade 3-4 toxicities reported more frequently for vinorelbine plus cisplatin than for pemetrexed plus cisplatin were febrile neutropenia (11.6% v 0.3%, respectively), neutropenia (81.1% v 22.7%, respectively), and anemia (9.3% v 2.8%, respectively). One treatment-related death occurred in each arm.
Conclusion: Although this study failed to show the superiority of pemetrexed plus cisplatin for patients with resected nonsquamous NSCLC, this regimen showed a better tolerability as adjuvant chemotherapy.