The Efficacy and Safety of Lenalidomide Oral Monotherapy in Patients with Mantle Cell Lymphoma Previously Treated with Bortezomib: Pooled Data from Two Phase II Studies (NHL-002 and NHL-003).

Introduction: Mantle-cell lymphoma (MCL) is an aggressive B-cell lymphoma that if not cured with aggressive chemoimmunotherapy and stem cell transplant is usually fatal. The intravenous proteasome inhibitor bortezomib produces an overall response rate (ORR) of 33% in patients with relapsed MCL (

Methods: Patients with relapsed or refractory MCL and measurable disease 2 cm after at least one prior treatment regimen including prior bortezomib were eligible. Patients received 25 mg of lenalidomide orally once daily on days 1–21 of every 28-day cycle. Therapy was continued as tolerated or until disease progression. The 1999 IWLRC methodology was used to assess response and progression.

Results: The 14 patients in this study were heavily pretreated with a median of 4 (2–6) prior treatments (including bortezomib) and 50% were bortezomib-refractory. Median age was 66 (45–84) years and 6 (43%) patients were female. Median time from diagnosis to lenalidomide treatment was 3.3 (0.7–7.6) years. The ORR with lenalidomide was 57% (8/14), including 21% (3/14) complete response (CR)/unconfirmed CR and 36% (5/14) partial responses. One (7%) patient had stable disease. The most common grade 3 or 4 adverse events were neutropenia (50%), thrombocytopenia (43%), anemia (21%), fatigue (21%), and leukopenia (21%). Neutropenic fever occurred in 7% of patients.

Conclusion: These results demonstrate that lenalidomide oral monotherapy is very effective with manageable side effects in patients with relapsed or refractory MCL who had received prior treatment with bortezomib.