Bendamustine induced neurotoxicity.

Bendamustine (Treanda, Cephalon) is a unique compound composed of an alkylating agent (a nitrogen mustard derivate) and a benzimidazole ring (similar to a purine analog).1 Originally developed in the 1960s, the rationale behind the drug was to use both its antimetabolite activity and alkylating properties to produce an effective drug with a lower toxicity profile than other alkylating agents.2 Currently, bendamustine is approved by the U.S. Food and Drug Administration for the treatment of chronic lymphocytic leukemia (CLL) and indolent non-Hodgkin lymphoma (NHL) refractory to rituximab (Rituxan, Genentech), and its efficacy is being investigated in a number of other histologies of NHL and multiple myeloma. Reported adverse effects have been limited mainly to hematologic and gastrointestinal toxicities.3,4 However, purine analogs are known to cause neurotoxicity, which may have a delayed onset.5 To date, no known report of neurologic side effects from the use of bendamustine exists in the literature.