Lenalidomide maintenance following high-dose therapy and autologous haematopoietic stem cell transplantation in chemo-resistant or high-risk non-Hodgkin lymphoma: A phase I/II study.

Improved maintenance treatments are needed for patients with relapsed/refractory aggressive lymphomas after autologous haematopoietic stem cell transplantation (ASCT). Several studies with lenalidomide have been found to have activity in the treatment of relapsed/refractory aggressive lymphomas. In the present phase I/II, single-arm, open-label study, 59 patients with high-risk relapsed non-Hodgkin lymphoma received pretransplant BEAM chemotherapy and ASCT followed by 12 months of maintenance lenalidomide once daily on Days 1-21 (28-day cycles) beginning at post-transplantation Day 100. The most common histologies were mantle cell lymphoma (56%) and diffuse large B-cell lymphoma (24%). The maximum tolerated dose in the dose-finding part of the study was 15 mg, but cytopenias led to the subsequent adoption of a 10 mg dose in the final study. Sixteen patients (27%) completed 12 cycles of lenalidomide maintenance. The most common reason for discontinuation was adverse events (31%). These were primarily haematologic, and 56% of patients experienced Grade 3-4 events. Two-year PFS rates (95% CIs) were 70% (56%-80%), 45% (19%-68%) and 81% (66%-90%); 2-year OS rates (95% CIs) were 91% (80%-96%), 93% (61%-99%) and 90% (76%-96%) in all patients, patients completing and patients not completing 12-month maintenance respectively. These results do not support the use of lenalidomide maintenance in this setting.