Phase II Study of Gemcitabine and Cisplatin in Patients with Previously Untreated Extensive Stage Small Cell Lung Cancer: Southwest Oncology Group Study 9718

Abstract

This phase II study (S9718) evaluated the antineoplastic activity and tolerability of the combination of gemcitabine and cisplatin in previously untreated patients with extensive stage small cell lung cancer (ES-SCLC). Chemonaive patients with ES-SCLC, received gemcitabine 1250 mg/m intravenously (IV) over 30 minutes on days 1 and 8 and cisplatin 75 mg/m IV over 30 to 60 minutes on day 1. Treatments were repeated every 21 days for a maximum of six cycles. A total of 88 patients were enrolled in the study; seven patients were not eligible and one did not receive treatment; 80 patients were fully assessable for survival, response, and toxicity. Objective response was observed in 42 patients (53%; 95% confidence interval [CI]: 41%-64%) with two patients (3%; 95% CI: 0%-8%) achieving a complete response. Median PFS was 5 months (CI, 4.2-5.9 months), and median overall survival was 8.8 months (95% CI: 7.8-9.5 months). The 1- and 2-year survival rates were 27.5% (95% CI: 17.7%-37.3%) and 4% (95% CI: 0%-8%), respectively. The most common toxicity was neutropenia. Grade 3 and 4 neutropenia was noted in 17 (21%) and 17 (21%) patients, respectively. Two patients developed febrile neutropenia, with subsequent full recovery. Twenty-one patients (23%) developed grade 3 thrombocytopenia. Grade 4 thrombocytopenia was seen in only one patient. The most common nonhematologic toxicities included grade 3 and 4 vomiting in 12 (21%) patients and fatigue in nine (10%) patients. Two patients (3%) died of respiratory infections while on treatment. The combination of gemcitabine and cisplatin is an active and reasonably well tolerated regimen for the treatment of ES-SCLC. It does not appear to offer any compelling advantages over other commonly used two drug regimens in this disease.