The present invention relates to methods of treating mammals affected by, for example, a hyperproliferative disease such as cancer, by administering a tumor-targeted superantigen and a chemotherapeutic agent, whereby the administration of the tumor-targeted superantigen and chemotherapeutic agent reduce the antibody response and enhance the T cell response. The superantigen, wild-type or modified, is fused to a target-seeking moiety, such as an antibody or an antibody active fragment. The combined administration of a superantigen and a chemotherapeutic agent provides enhanced therapeutic effects in a treated animal.