Preliminary results from a phase II study of lenalidomide oral monotherapy in relapsed/refractory indolent non-Hodgkin lymphoma

Abstract

8066 Background: Lenalidomide, an immunomodulatory drug, is approved in the US for treatment of relapsed/refractory multiple myeloma and myelodysplastic syndromes associated with a deletion 5q[31] cytogenetic abnormality. Lenalidomide also has activity in chronic lymphocytic leukemia and cutaneous T-cell lymphoma. This study was designed to assess the safety and efficacy of lenalidomide monotherapy in patients with relapsed/refractory indolent non-Hodgkin's lymphoma (NHL). Methods: Patients with relapsed/refractory indolent NHL with measurable disease after at least 1 prior treatment regimen were eligible. Patients received 25 mg lenalidomide orally once daily on Days 1–21 every 28 days and continued therapy for 52 weeks as tolerated or until disease progression. Response and progression were evaluated using the IWLRC methodology. Results: As of enrollment cut-off, 43 patients received drug and 27 were evaluable for response. The median age was 63 (43–82) and 12 were female. Histology was small lymphocytic lymphoma [SLL] (n=12), follicular center lymphoma grades 1,2 [FCL] (n=12) and nodal marginal B-cell lymphoma [NML] (n=3). Median time from diagnosis to lenalidomide was 4.3 (0.4- 24) years and median number of prior treatment regimens was 3 (1–17). Seven patients (26%) exhibited an objective response (2 complete responses (CR), 1 complete response unconfirmed (CRu) and 4 partial responses (PR)), 9 had stable disease (SD) for a tumor control rate (TCR) of 59% and 11 progressive disease (PD). Responses were produced in each of the indolent histologic subtypes studied: SLL (3/12), FCL (3/12) and NML (1/3). Since most responses develop at ≥ 4 months, additional responses may be seen in early SD patients with longer follow-up. Five patients (12%) exhibited Grade 4 neutropenia, and Grade 3 adverse events were neutropenia (16%) and thrombocytopenia (14%). Conclusion: Lenalidomide oral monotherapy is active with manageable side effects in relapsed/refractory indolent NHL. [Table: see text]