Five-year follow-up of lenalidomide plus rituximab as initial treatment of mantle cell lymphoma.

We report 5-year follow-up of a multicenter phase 2 study of lenalidomide plus rituximab (LR) as initial treatment of mantle cell lymphoma (MCL). The regimen includes induction and maintenance with the LR doublet. Treatment was continuous until progression, with optional discontinuation after 3 years. The median age of the 38 participants was 65 years, with MCL international prognostic index scores balanced among low, intermediate, and high risk (34%, 34%, and 32%, respectively). Twenty-seven (75%) of the 36 evaluable patients completed ≥3 years of study treatment. At a median follow-up of 64 months (range, 21-78), the 3-year progression-free survival (PFS) and overall survival (OS) were 80% and 90%, respectively, with 5-year estimated PFS and OS of 64% and 77%, respectively. During maintenance, hematologic adverse events (AEs) included asymptomatic grade 3 or 4 cytopenias (42% neutropenia, 5% thrombocytopenia, 3% anemia) and mostly grade 1 or 2 infections managed in the outpatient setting (45% upper respiratory infection, 21% urinary tract infection, 13% sinusitis, 11% cellulitis, 8% pneumonia). Nonhematologic AEs, such as constitutional and inflammatory symptoms, occurred at reduced frequency and intensity compared with induction. A peripheral blood minimal residual disease (MRD) assay (clonoSEQ) showed MRD-negative complete remission in 8 of 10 subjects who had completed ≥3 years of treatment and with available samples for analysis. With longer follow-up, LR continues to demonstrate durable responses and manageable safety as initial induction and maintenance therapy for MCL (ClinicalTrials.gov NCT01472562).

Lenalidomide plus Rituximab as Initial Treatment for Mantle-Cell Lymphoma.

BACKGROUND: Mantle-cell lymphoma is generally incurable. Initial treatment is not standardized but usually includes cytotoxic chemotherapy. Lenalidomide, an immunomodulatory compound, and rituximab, an anti-CD20 antibody, are active in patients with recurrent mantle-cell lymphoma. We evaluated lenalidomide plus rituximab as a first-line therapy. METHODS: We conducted a single-group, multicenter, phase 2 study with induction and maintenance phases. During the induction phase, lenalidomide was administered at a dose of 20 mg daily on days 1 through 21 of every 28-day cycle for 12 cycles; the dose was escalated to 25 mg daily after the first cycle if no dose-limiting adverse events occurred during the first cycle and was reduced to 15 mg daily during the maintenance phase. Rituximab was administered once weekly for the first 4 weeks and then once every other cycle until disease progression. The primary end point was the overall response rate. Secondary end points included outcomes related to safety, survival, and quality of life. RESULTS: A total of 38 participants were enrolled at four centers from July 2011 through April 2014. The median age was 65 years. On the basis of the Mantle Cell Lymphoma International Prognostic Index scores, the proportions of participants with low-risk, intermediate-risk, and high-risk disease at baseline were similar (34%, 34%, and 32%, respectively). The most common grade 3 or 4 adverse events were neutropenia (in 50% of the patients), rash (in 29%), thrombocytopenia (in 13%), an inflammatory syndrome ("tumor flare") (in 11%), anemia (in 11%), serum sickness (in 8%), and fatigue (in 8%). At the median follow-up of 30 months (through February 2015), the overall response rate among the participants who could be evaluated was 92% (95% confidence interval [CI], 78 to 98), and the complete response rate was 64% (95% CI, 46 to 79); median progression-free survival had not been reached. The 2-year progression-free survival was estimated to be 85% (95% CI, 67 to 94), and the 2-year overall survival 97% (95% CI, 79 to 99). A response to treatment was associated with improvement in quality of life. CONCLUSIONS: Combination biologic therapy consisting of lenalidomide plus rituximab was active as initial therapy for mantle-cell lymphoma. (Funded by Celgene and Weill Cornell Medical College; ClinicalTrials.gov number, NCT01472562.).