Efficacy of bendamustine in rituximab-refractory indolent B-cell non-Hodgkin lymphoma: review of a pivotal trial.

B-cell malignancies, including B-cell non-Hodgkin's lymphoma (NHL) and chronic lymphocytic leukemia (CLL), are the most common hematologic malignancies in the western world. Although excellent response rates are achieved with standard chemoimmunotherapy, patients often relapse and additional treatment is necessary. Bendamustine, a unique cytotoxic agent with alkylating and antimetabolite properties, has been used for decades in Germany for NHL, CLL and multiple myeloma. In 2008, bendamustine was approved by the US FDA for the treatment CLL and rituximab-refractory indolent B-cell NHL. The approval in NHL was based on the results of this multicenter, single-arm trial in which patients with rituximab-refractory indolent NHL received bendamustine 120 mg/m(2) on days 1 and 2 of each 21-day cycle for six to eight cycles. The primary end points were overall response rate and median duration of response, and the secondary end points were progression-free survival and the safety profile. Bendamustine demonstrated significant efficacy with an overall response rate of 75% median duration of response of 9.2 months and median progression-free survival of 9.3 months, as well as easy tolerability. The most common toxicities were nausea, myelosuppression and infection. These results confirm bendamustine's role in rituximab-refractory indolent B-cell NHL.