Safety and efficacy of lenalidomide in combination with rituximab in recurrent indolent non-follicular lymphoma: final results of a phase II study conducted by the Fondazione Italiana Linfomi

We present the final results of a Phase II study that evaluated safety and efficacy of lenalidomide in combination with rituximab in 39 patients with recurrent small lymphocytic lymphoma (N=18), marginal zone lymphoma (N=8), or lymphoplasmacytic lymphoma (N=13). Patients received oral doses of lenalidomide 20 mg once daily on days 1-21 and rituximab 375 mg/m2 on day 14 of each 28-day course. Patients received up to 6 courses. The overall response was 54%, with a complete response of 21%. At 2 years, progression free survival, duration of remission, and overall survival were 45%, 76%, and 78%, respectively. The evaluation of treatment response by histology showed an overall response rates of 75%, 46%, and 50%, in marginal zone, lymphoplasmacytic and small lymphocytic lymphoma, respectively. Histology-based estimates of remission durations at 2 years were 100%, 100%, and 51% for marginal zone, lymphoplasmacytic, and small lymphocytic lymphomas, respectively. A log rank test showed that the marginal zone and lymphoplasmacytic lymphoma curves were marginally significantly different from the small lymphocytic lymphoma curve. Our results demonstrated that patients with recurrent marginal zone and lymphoplasmacytic lymphomas that responded to the combination treatment had long-lasting responses. Of note, no other studies have published the effects of this combination treatment on patients with relapsed lymphoplasmacytic lymphoma. Our findings showed a mild, predictable, and manageable toxicity profile. Confirmation of these results in Phase III trials will facilitate moving towards a chemotherapy-free approach in the management of indolent non-Hodgkin lymphoma. ClinicalTrials.gov; Identifier: NCT01830478.