Combination of lenalidomide and rituximab in elderly patients with relapsed or refractory diffuse large B-cell lymphoma: A phase 2 trial

Diffuse large B-cell lymphoma (DLBCL) is the most common subtype of aggressive non-Hodgkin lymphoma and despite recent chemotherapeutic advances up to half of all patients relapse. We conducted a phase two trial: oral lenalidomide in combination with rituximab is active in elderly patients with relapsed/refractory DLBCL with a high percentage of patients achieving a continuous CR after lenalidomide maintenance. Background: Diffuse large B-cell lymphoma (DLBCL) is the most common subtype of aggressive non-Hodgkin lymphoma and despite recent chemotherapeutic advances up to half of all patients relapse. Here we report the results from a phase 2, single-arm, single-center trial evaluating the safety and efficacy of lenalidomide plus rituximab in elderly patients with relapsed or refractory DLBCL. Patients and Methods: Between March and June 2009, elderly patients (65 years of age or older) with relapsed/refractory DLBCL who had been heavily pretreated were recruited. Oral lenalidomide (20 mg/d for 21 days of each 28-day cycle) was initiated for four cycles and rituximab (375 mg/m2) was administered on day 1 and day 21 of each 28-day cycle for four cycles. After this induction phase, patients achieving a complete response (CR), partial response (PR), or stable disease (SD) were given lenalidomide maintenance therapy at the same schedule for another 8 months. Results: A total of 23 patients with a median of three prior treatments (range, 2 to 8) were included. The overall response rate (CR + PR) at the end of the induction phase was 35% (n = 8). Ten patients (7 CR, 1 PR, and 2 SD patients) were eligible for lenalidomide maintenance and 8 of these patients achieved a CR. Adverse events were manageable and the most common included neutropenia and thrombocytopenia. Conclusion: Oral lenalidomide in combination with rituximab is active in elderly patients with relapsed/refractory DLBCL with a high percentage of patients achieving a continuous CR after lenalidomide maintenance.