Phase II multicenter study of bendamustine plus rituximab in patients with relapsed indolent B-cell and mantle cell non-Hodgkin's lymphoma

Purpose: Bendamustine HCl is a bifunctional mechlorethamine derivative with clinical activity in the treatment of non-Hodgkin's lymphoma. This study evaluated bendamustine plus rituximab in 67 adults with relapsed, indolent B-cell or mantle cell lymphoma without documented resistance to prior rituximab. Patients and Methods: Patients received rituximab 375 mg/m² intravenously on day 1 and bendamustine 90 mg/m² intravenously on days 2 and 3 of each 28-day cycle for four to six cycles. An additional dose of rituximab was administered 1 week before the first cycle and 4 weeks after the last cycle. Sixty-six patients (median age, 60 years) received at least one dose of both drugs. Results: Overall response rate was 92% (41% complete response, 14% unconfirmed complete response, and 38% partial response). Median duration of response was 21 months (95% CI, 18 to 24 months). Median progression-free survival time was 23 months (95% CI, 20 to 26 months). Outcomes were similar for patients with indolent or mantle cell histologies. The combination was generally well tolerated; the primary toxicity was myelosuppression (grade 3 or 4 neutropenia, 36%; grade 3 or 4 thrombocytopenia, 9%). Conclusion: Bendamustine plus rituximab is an active combination in patients with relapsed indolent and mantle cell lymphoma.