A drug used with bendamustine to treat follicular lymphoma that has come back or has not gotten better after treatment with rituximab. It is also used with chlorambucil to treat chronic lymphocytic leukemia (CLL) that has not already been treated. It is also being studied in the treatment of other types of cancer. Gazyva binds to a protein called CD20, which is found on B cells (a type of white blood cell) and some types of leukemia and lymphoma cells. This may help the immune system kill cancer cells. Gazyva is a type of monoclonal antibody. Also called obinutuzumab.