Rituximab and Stem Cell Transplantation Produces Durable Remissions in Mantle Cell Lymphoma.

Introduction: Mantle cell lymphoma (MCL) is a CD20+ malignancy comprising up 5% of non-Hodgkin’s lymphomas, and has a poor prognosis under standard chemotherapy. The HyperCVAD-M/A regimen (fractionated high-dose cyclophosphamide, vincristine, doxorubicin and prednisolone alternated with methotraxate and cytarabine) has yielded encouraging results when combined with autologous stem cell transplantation (ASCT) in MCL, with 5-year failure-free survival of 54% and overall survival 72%. In an effort to improve these results further, we have combined rituximab in vivo purging and post-transplant consolidation with HyperCVAD-M/A plus ASCT.

Methods: Patients aged <65 years with previously untreated or relapsed MCL were treated with four courses of HyperCVAD-M/A followed by four once-weekly doses of rituximab 375mg/m² as purging prior to stem cell mobilization and harvesting, high-dose chemotherapy (ICT-CY or BEAM), stem cell reinfusion and four further doses of rituximab immunotherapy post-transplant.

Results: Of the 34 patients enrolled so far, 15 (12 male, 3 female; 12 previously untreated) have been transplanted. The median age was 52 years (range 47–63 years). After the final post-ASCT immunotherapy all 15 patients were in clinical complete remission. With a median follow-up of 30 months from diagnosis (range 7–52 months), 14 patients remain alive with 13 in first complete remission. One patient died 15 months post-ASCT without evidence of disease recurrence. Kaplan-Meier estimates of 4-year overall and event-free survival are 93.3% and 86.6% respectively.

Conclusions: This approach seems safe and feasible and produces durable remissions; longer follow-up of a more patients will be required to assess the effect of the procedure on survival.