The active ingredient in a drug used to treat chronic lymphocytic leukemia (CLL). It is also used to treat slow-growing B-cell non-Hodgkin lymphoma (NHL) that got worse during or within 6 months after treatment with rituximab. It is also being studied in the treatment of other types of cancer. Bendamustine damages the cell’s DNA and may kill cancer cells. It is a type of alkylating agent.