MUNICH-The prognosis for patients with mantle cell lymphoma (MCL) remains poor despite investigations of multiple combination chemotherapy strategies. The 5- year overall survival rate is 27% and less than 11% of patients are disease free at 5 years. Because of the beneficial effects of rituximab (Rituxan) in non-Hodgkin's lymphoma and its favorable tolerability profile when added to chemotherapy, Wolfgang Hiddemann, MD, PhD, professor of internal medicine at Ludwig-Maximilians- University in Munich, and other members of the German Low Grade Lymphoma Study Group (GLSG) conducted two prospective, randomized trials of rituximab plus combination chemotherapy (ASH abstract 339). In the first-line treatment trial, the GLSG compared cyclophosphamide (Cytoxan, Neosar), doxorubicin, vincristine (Oncovin), and prednisone (CHOP) vs rituximab plus CHOP (RCHOP) against follicular lymphoma, immunocytoma, and mantle cell lymphomas.[ 5] The 272 patients evaluable for response included 62 patients with MCL (see Table 1). Treatment with R-CHOP resulted in a significantly (P = .019) greater overall response rate compared with CHOP treatment alone. Furthermore, the time to treatment failure was 435 days for the CHOP-alone treatment group, but was not reached in the R-CHOP treatment group. Importantly, a subset analysis of the 62 patients with mantle cell lymphoma demonstrated a significantly greater overall response rate of 97% for patients treated with R-CHOP compared with 69% for patients treated with CHOP (P = .004). Relapsed, Refractory Disease As second-line therapy, patients with relapsed or refractory lymphoma, including follicular lymphoma, immunocytoma, and mantle cell lymphoma, were treated with fludarabine (Fludara), cyclophosphamide, and mitoxantrone (Novantrone), the FCM regimen, or with rituximab plus FCM (R-FCM). In this study, 94 patients were evaluable, including 35 patients with MCL. The overall response rates for both treatment groups were comparable (see Table 1). Progression-free survival, however, was significantly longer in the R-FCM treatment group compared with the FCM treatment group (median, 483 days vs 213 days, P = .048). Collective Impact The results of these two studies suggest that the addition of rituximab to chemotherapy in both first-line and second-line treatment improves overall response rates and significantly improves progression-free survival in MCL compared with chemotherapy alone. Overall response rates with singleagent rituximab in MCL have ranged from approximately 20% to 46%,[6- 12] with median response duration as high as approximately 438 days.  Although the investigators did not study rituximab as single-agent therapy, the current studies do support further investigation of rituximab plus combination chemotherapy. Based on these results, rituximab plus chemotherapy may become a new standard for the treatment of MCL.
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