The present invention relates to immunotherapies that are based on depletion of CD37-positive cells such as B-cells. The present invention provides methods for reduction of CD37-positive cells such as B-cells in an individual/patient using a combination of CD37 antibody/antibodies and bendamustine. The combination of CD37 antibodies and bendamustine is shown to have a synergistic effect. The application further provides materials and methods for treatment of diseases involving aberrant B-cell activity.
