Bendamustine, brand name Treanda, is a chemotherapeutic agent that displays a unique pattern of cytotoxicity compared with conventional alkylating agents. Treanda is indicated for the treatment of patients with chronic lymphocytic leukemia (CLL), in addition Trenda in phase III of clinical trial for the treatment patients with indolent B-cell non-Hodgkin lymphoma (NHL) that has progressed during or within six months of treatment with rituximab or a rituximab-containing regimen. Bendamustine is a bifunctional mechlorethamine derivative. Mechlorethamine and its derivatives dissociate into electrophilic alkyl groups. These groups form covalent bonds with electron-rich nucleophilic moieties. The bifunctional covalent linkage can lead to cell death via several pathways. The exact mechanism of action of bendamustine remains unknown. Molecular analyses have revealed that bendamustine differs from other alkylating agents in its mechanism of action. Differences have been observed about its effects on DNA repair and cell cycle progression. Moreover, bendamustine can induce cell death through both apoptotic and nonapoptotic pathways, thereby retaining activity even in cells without a functional apoptotic pathway. Bendamustine possesses the typical adverse reactions for the nitrogen mustards, and include nausea, fatigue, vomiting, diarrhea, fever, constipation, loss of appetite, cough, headache, unintentional weight loss.