Phase II study of bendamustine in relapsed chemotherapy sensitive or resistant small-cell lung cancer

Introduction: To determine the time to progression (TTP), response rate (RR), and toxicity for North American patients with relapsed small-cell lung cancer (SCLC) treated with bendamustine in the second- or third-line setting. Methods: Patients with relapsed, histologically confirmed SCLC were eligible for enrollment on study. The study population included patients with both chemotherapy-sensitive and chemotherapyresistant disease treated with up to two prior lines of chemotherapy. Patients were treated with 120 mg/m2 of bendamustine on days 1 and 2 of a 21-day cycle for up to six cycles. Primary end point was TTP; secondary end points included toxicity, RR, and overall survival. Results: Fifty-nine patients were accrued, 50 patients met eligibility for enrollment. The median age of patients was 62, and 56% were men. Twenty-nine patients (58%) had chemotherapy-sensitive disease. Median TTP was 4.0 months (95% confidence interval [CI], 3.3-5.4), median overall survival was 4.8 months (95% CI, 3.8-6.3), and the RR was 26% (95% CI, 13.3%-39.5%). Patients with chemosensitive disease had a median TTP of 4.2 months (95% CI, 3.3-6.0) compared with 3.4 months (95% CI, 2.7-∞) for chemotherapy-resistant disease. The RR was 33% (95% CI, 14.2%-51.8%) in patients with chemosensitive disease and 17% (95% CI, 0%-34.4%) in those with chemoresistant disease. The most common grade 3/4 adverse events were fatigue (20%), dyspnea (12%), and anemia (12%). Conclusion: Bendamustine has modest activity in relapsed SCLC similar to other agents evaluated in this patient population.