Bendamustine therapy for relapsed or refractory low grade B cell lymphoma and mantle cell lymphoma

Abstract

Purpose: Bendamustine (Ben) is an alkylating agent consisting of three structural elements: a 2-chloroethylamine alkylating group; a butyric acid side chain; and a benzimidazole ring. A number of randomized controlled trials have examined the effect of Ben compared to other chemotherapy regimens in patients ( pts) with lymphoma. Here, we examined the efficacy and safety of Ben for pts with relapsed or refractory mantle cell lymphoma (MCL) and low grade B-cell lymphoma (LGBCL) including follicular lymphoma (FL). Patients and methods: Previously treated 50 pts (37 FL, 5 MCL, others 8; male 25, female 25) were treated with Ben as a salvage therapy between Dec 2010 and Jan 2015. The median age was 68 years (37-84). Seven pts were heavily pretreated (4 and over previous regimens). Prior autologous stem cell transplantation, fludarabine, and Zevalin were also included. Pts received Ben 60-120 mg/m2 on days 1 and 2 every 21-28 days with G-CSF support. Fory one pts received rituximab 375 mg/m2 combined with Ben. Nine pts were retreated with Ben. Results: The overall response rate (ORR) was 88% (80% complete remission [CR], 11% partial remission [PR]) in LGBCL, and 60% (40% CR, 20% PR) in MCL, respectively. ORRs according to prior regimen number in LGBCL were 89% in one regimen and 94% in 2 and over regimens. Median progression free survival was 23months in LGBCL and 15 months on MCL. Eight pts who had been retreated with Ben obtained CR or PR. Non-hematological adverse events were infrequent except nausea (50%). Grade 2 phlebitis was observed in 8%. Grade 3 or 4 leukopenia (68%) and reactivation of cytomegalovirus (21.2%) were observed. Conclusion: Ben is feasible and effective in relapsed or refractory LGBCL and MCL. It might be used earlier in the treatment strategy of these lymphomas and in combination with other active drugs such as rituximab.