Phase II Trial of Revlimid® and Rituximab for Relapsed or Refractory Chronic Lymphocytic Leukemia (CLL)

The Chronic Lymphocytic Leukemia (CLL) Research Consortium (CRC) is conducting a two-arm, multicenter phase II trial of Revlimid® and rituximab for Relapsed or Refractory Chronic Lymphocytic Leukemia (CLL) for patients under the age of 65 and patients 65 years and older. Revlimid® (lenalidomide) a derivative of thalidomide with immune-modulating properties. Revlimid® is FDA approved for treatment of relapsed multiple myeloma and 5q- myelodysplastic syndrome. Revlimid® has promising clinical activity, in both previously treated and treatment naive CLL in early clinical trials. However, the mechanism(s) whereby Revlimid® is active in CLL is unknown. Rituximab (Rituxan®) is a monoclonal antibody that binds to CD20 expressed on normal and leukemia B cells. Rituximab is approved for the treatment of CLL. In preclinical models of lymphoma Revlimid improved the activity of Rituximab. In clinical studies of relapsed and/or refractory CLL the combination Revlimid and Rituximab was associated with better therapeutic effects compared with what was historically observed with either agent alone. The purpose of this study is to evaluate the safety and activity of the combination of Revlimid® and rituximab in relapsed or refractory CLL, elucidate the mechanism of action of Revlimid® in CLL, and to assess whether prognostic factors might predict those patients likely to benefit from this therapy in the future. The primary objective of this study is to determine the overall response rate (ORR) of the combination of Revlimid® and rituximab in previously treated CLL patients for those age 65 years and above and those younger than 65. Secondary objectives will evaluate the safety of the combination of Revlimid® and Rituximab, response duration, improvement in hematologic parameters, activity of the combination in high-risk CLL subsets, the significance of the tumor flare reaction and to compare the activity of this regimen when administered to previously treated patients to our protocol in the front line setting and to compare these outcomes for both arms of the study. All patients will receive treatment with Revlimid® starting at a low dose that will be slowly dose escalated based on individual patient tolerability. The combination of Revlimid and Rituximab will be administered for a maximum of 7 cycles. Patients with residual leukemia following seven cycles of treatment with the combination may elect to continue on protocol for an additional 6 cycles of single agent Revlimid® consolidation. All patients will have baseline assessment of known CLL prognostic factors through the CRC tissue core. These known prognostic features in CLL together with novel prognostic factors will be evaluated for the ability to predict response to treatment with Revlimid® and the combination of Revlimid® and Rituximab.