An international phase II trial of single-agent lenalidomide for relapsed or refractory aggressive B-cell non-Hodgkin's lymphoma

Background: Lenalidomide is an immunomodulatory agent with antitumor activity in B-cell malignancies. This phase II trial aimed to demonstrate the safety and efficacy of lenalidomide in patients with relapsed or refractory diffuse large B-cell lymphoma (DLBCL), mantle cell lymphoma (MCL), follicular grade 3 lymphoma (FL-III), or transformed lymphoma (TL). Methods: Patients received oral lenalidomide 25 mg on days 1-21 every 28 days as tolerated or until progression. The primary end point was overall response rate (ORR). Results: Two hundred and seventeen patients enrolled and received lenalidomide. The ORR was 35% (77/217), with 13% (29/217) complete remission (CR), 22% (48/217) partial remission, and 21% (45/217) with stable disease. The ORR for DLBCL was 28% (30/108), 42% (24/57) for MCL, 42% (8/19) for FL-III, and 45% (15/33) for TL. Median progression-free survival for all 217 patients was 3.7 months [95% confidence interval (CI) 2.7-5.1]. For 77 responders, the median response duration lasted 10.6 months (95% CI 7.0-NR). Median response duration was not reached in 29 patients who achieved a CR and in responding patients with FL-III or MCL. The most common adverse event was myelosuppression with grade 4 neutropenia and thrombocytopenia in 17% and 6%, respectively. Conclusion: Lenalidomide is well tolerated and produces durable responses in patients with relapsed or refractory aggressive non-Hodgkin's lymphoma.