Abstract 3694

Poster Board III-630

[Background and Purpose]

Bendamustine hydrochloride is a bifunctional alkylating agent with novel mechanisms of action. Although bendamustine is known to have anti-tumor activity against indolent B-NHL as a single agent, efficacy in MCL with bendamustine monotherapy has not been reported. To assess the efficacy and toxicity of bendamustine in patients with relapsed indolent B-NHL and MCL, we conducted a multicenter phase II study.

[Patients and Methods]

Patients diagnosed with relapsed or refractory indolent B-NHL or MCL, 75= or >age= or >20, and PS 0-1 (ECOG) were enrolled in the study. Bendamustine was administered intravenously at a dose of 120 mg/m2 infused over 60 minutes on days 1 and 2 of each 21-day treatment cycle for up to 6 cycles (minimum of 3 cycles). The primary endpoint was the overall response rate (ORR). Tumor response was assessed by a central radiological review committee according to the International Workshop Criteria for NHL (1999).


A total of 69 patients were enrolled and treated, including 52 (75%) cases of follicular lymphoma (FL) and 11 (16%) cases of MCL, ages 33 to 75 years, with predominantly stage III/IV indolent B-NHL (86%) or MCL (64%). The median number of unique prior therapies was two (range, 1 to 16), and sixty-six patients (96%) had received rituximab as a prior therapy. Twenty-nine patients (42%) completed the planned six cycles of chemotherapy, with fifty patients (72%) receiving 3 or more cycles. Dose reduction of bendamustine was required in 11 patients (16%). The ORR was 91% (63 of 69 patients; 95% CI, 82% to 97%) with a complete response (CR) rate of 67% (%CR), including %CRu (46 of 69 patients; 95% CI, 54% to 78%). The ORR in FL and MCL was 90% and 100%, respectively. The %CR in FL and MCL was 66% and 73%, respectively. Median progression-free survival (PFS) for all 69 patients was not reached at the median follow-up duration of 248 days (39-359 days). Median PFS for indolent B-NHL (58) and MCL (11) patients was not reached at the median follow-up duration of 254 days and 226 days, respectively. Hematologic toxicities, including grade 4 lymphopenia (72%) and neutropenia (48%), were the most frequently reported toxicities in patients. Non-hematologic toxicities were mild, with no grade 4 non-hematologic toxicity recorded. The most frequently reported grade 3 non-hematologic toxicities were GI toxicities (9%) including grade 3 vomiting (4%) and anorexia (3%), and infections (7%) which included one case of grade 3 febrile neutropenia, pneumonia, herpes infection, and viral pharyngitis.


Bendamustine monotherapy is a highly effective and less toxic treatment in patients with relapsed or refractory indolent B-NHL and MCL who have been pretreated (96%) with rituximab. It is noteworthy that a very high complete response rate (73%) was achieved in relapsed or refractory MCL patients although the number of patients was relatively small.


No relevant conflicts of interest to declare.

Author notes


Asterisk with author names denotes non-ASH members.