Randomized Trial of Lenalidomide Alone Versus Lenalidomide Plus Rituximab in Patients With Recurrent Follicular Lymphoma: CALGB 50401 (Alliance)

Abstract

Purpose Lenalidomide and rituximab (LR) are active agents in follicular lymphoma (FL). Combination regimens have not been previously assessed in randomized studies. Patients and Methods The Cancer and Leukemia Group B (Alliance) 50401 trial is a randomized phase II trial studying rituximab (375 mg/m2 weekly for 4 weeks), lenalidomide (15 mg per day on days 1 to 21, followed by 7 days of rest, in cycle 1 and then 20 mg per day on days 1 to 21, followed by 7 days of rest, in cycles 2 to 12), or LR. The rituximab-alone arm was discontinued as a result of poor accrual. Eligibility included recurrent FL and prior rituximab with time to progression of ≥ 6 months from last dose. Aspirin or heparin was recommended for patients at high thrombosis risk. Results Ninety-one patients (lenalidomide, n = 45; LR, n = 46) received treatment; median age was 63 years (range, 34 to 89 years), and 58% were intermediate or high risk according to the Follicular Lymphoma International Prognostic Index. In the lenalidomide and LR arms, grade 3 to 4 adverse events occurred in 58% and 53% of patients, with 9% and 11% of patients experiencing grade 4 toxicity, respectively; grade 3 to 4 adverse events included neutropenia (16% v 20%, respectively), fatigue (9% v 13%, respectively), and thrombosis (16% [n = 7] v 4% [n = 2], respectively; P = .157). Thirty-six percent of lenalidomide patients and 63% of LR patients completed 12 cycles. Lenalidomide alone was associated with more treatment failures, with 22% of patients discontinuing treatment as a result of adverse events. Dose-intensity exceeded 80% in both arms. Overall response rate was 53% (20% complete response) and 76% (39% complete response) for lenalidomide alone and LR, respectively (P = .029). At the median follow-up of 2.5 years, median time to progression was 1.1 year for lenalidomide alone and 2 years for LR (P = .0023). Conclusion LR is more active than lenalidomide alone in recurrent FL with similar toxicity, warranting further study in B-cell non-Hodgkin lymphoma as a platform for addition of novel agents.