PURPOSE: Nivolumab showed durable responses in patients with small cell lung cancer (SCLC). A randomized phase II study investigating nivolumab plus cisplatin/carboplatin and etoposide (PE) versus PE for patients with untreated extensive-stage (ES) SCLC was conducted.
METHODS: Patients with untreated ES-SCLC, Eastern Cooperative Oncology Group performance status 0-1, were randomized 1:1 to nivolumab 360 mg intravenously (IV) plus cisplatin 75 mg/m(2) or carboplatin area under the curve 5 on day 1 and etoposide 100 mg/m(2) (PE) on days 1-3 every 21 days for four cycles followed by nivolumab 240 mg intravenously (arm A) every 2 weeks on a 6-week cycle for up to 2 years or PE alone (Arm B) for 4 cycles followed by observation. The primary endpoint was progression-free survival (PFS). The primary comparison of PFS used a logrank test stratified on the randomization stratification factors with a one-sided type I error rate of 10%. Secondary endpoints included overall survival (OS), objective response rate (ORR), and safety.
RESULTS: Overall, 160 patients were enrolled; 144 patients were treated and constituted the primary analysis. The median PFS was 5.5 months (95% confidence interval [CI], 4.3-5.9 months) on arm A, and 4.9 months (95% CI, 4.5-5.7 months) on arm B (hazard ratio, 0.78; p = .083). The estimated median OS was 11.2 months (95% CI, 8.8-14.2 months) on arm A and 8.1 months (95% CI, 7.2-9.6 months) on arm B (hazard ratio, 0.71; p = .059).
CONCLUSION: The combination of PE and nivolumab improves both PFS and OS for patients with ES-SCLC. No new safety signals were observed.