Phase 2 trial of rituximab plus hyper-CVAD alternating with rituximab plus methotrexate-cytarabine for relapsed or refractory aggressive mantle cell lymphoma

BACKGROUND. Relapsed or refractory mantle cell lymphoma has a very poor prognosis. The authors evaluated the response rates and survival times of patients treated with an intense regimen known to be effective against untreated aggressive mantle cell lymphoma: rituximab plus hyper-CVAD (cyclophosphamide, vincristine, doxorubicin, and dexamethasone) alternating with rituximab plus methotrexate-cytarabine. METHODS. In this prospective, open-label, phase 2 study, patients received this combination for 6 to 8 cycles. Twenty-nine patients were evaluable for response. RESULTS. The median number of cycles received was 5 (range, 1-7 cycles), and the overall response rate was 93% (45% complete response [CR] or CR unconfirmed [CRu] and 48% partial response [PR]). All 5 patients previously resistant to treatment had a response (1 CR, 4 PR), and both patients whose disease did not change in response to prior therapy had PRs. Toxic events occurring in response to the 104 cycles given included neutropenic fever (11%), grade 3 or 4 neutropenia (74%), and grade 3 or 4 thrombocytopenia (63%). There were no deaths from toxicity. At a median follow-up of 40 months (range, 5-48 months), the median failure-free survival time was 11 months with no plateau in the survival curve. CONCLUSIONS. This combination chemotherapy was effective for refractory/relapsed mantle cell lymphoma.