Phase II study of gemcitabine and cisplatin in patients with previously untreated extensive stage small cell lung cancer: Southwest Oncology Group study 9718

Background: 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). Methods: Chemonaive patients with ES,-SCLC, received gemcitabine 1250 mg/m(2) intravenously (IV) over 30 minutes on days I and 8 and cisplatin 75 mg/m(2) IV over 30 to 60 minutes on day 1. Treatments were repeated every 21 days for a maximum of six cycles. Results: 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 [Cl]: 41%-64%) with two patients (3%; 95% Cl: 0%-8%) achieving a complete response. Median PFS was 5 months (CL 4.2-5.9 months), and median overall survival was 8.8 months (95% Cl: 7.8-9.5 months). The 1- and 2-year survival rates were 27.5% (95% Cl: 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.. Conclusion: 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.