Phase II trial of weekly dose-dense paclitaxel in extensive-stage small cell lung cancer: cancer and leukemia group B study 39901.

INTRODUCTION: Paclitaxel is an active agent in extensive-stage (ES) small cell lung cancer (SCLC). Nevertheless, the optimal schedule is uncertain. A dose-dense schedule was previously evaluated in a Cancer and Leukemia Group B study of patients with non-SCLC, resulting in a 42% response rate and median survival of 12.3 months. Because of these promising results, this dose and schedule of paclitaxel was evaluated in patients with ES-SCLC.
METHODS: Patients were eligible for this phase II trial (Cancer and Leukemia Group B 39901) if they had documented ES-SCLC, no prior chemotherapy, and performance status of 0 to 2. Paclitaxel was administered as an intravenous infusion at 150 mg/m2 over 3 hours weekly for 6 consecutive weeks every 8 weeks.
RESULTS: Thirty-six patients with median age of 65 were enrolled. Of them 25 were men and 33 with a performance status 0 to 1. A median of two 8-week cycles were delivered. The percent of patients with grade 3/4 toxicity included neutropenia 22%, anemia 9%, febrile neutropenia 6%, fatigue 20%, sensory neuropathy 26%, motor neuropathy 11%, and dyspnea 17%. There were two treatment-related deaths, both from pneumonitis. The overall response rate was 33% (3% complete response and 30% partial response). Median progression-free and overall survivals were 3.7 and 9.2 months, respectively. One-year progression-free and overall survivals were 17% and 36%, respectively.
CONCLUSIONS: For patients with ES-SCLC, dose-dense weekly paclitaxel was associated with fairly mild hematologic toxicity. Nevertheless, nonhematologic toxicities, including neuropathy, fatigue, and dyspnea required frequent dose delays and reductions. The overall response rate is disappointing and much lower than that seen with standard platinum-based combinations. Paclitaxel in this dose and schedule should not be used as front-line therapy for patients with ES-SCLC.