CD3-Bispecific Monoclonal Antibodies: A Novel Therapeutic Approach for Complex and Multifactorial Diseases

Monoclonal antibodies (mAbs) have witnessed significant advancements in recent years, offering promising therapeutic options for the management of complex and multifactorial diseases. Despite their success, conventional mAbs exhibit limitations such as restricted targeting capacity and suboptimal immune activation, which has driven the development of bispecific monoclonal antibodies (BsAbs) capable of engaging multiple antigens simultaneously. Among these, CD3-bispecific mAbs have emerged as a potent class of immunotherapeutics, capable of activating T cells and inducing T cell-mediated cytotoxicity against target cells, particularly in cancer immunotherapy. This review highlights several representative formats of BsAbs, elucidates their underlying mechanisms of action, and discusses current design strategies for CD3-bispecific mAbs. Emphasis is placed on optimizing their therapeutic efficacy while minimizing adverse effects, supported by recent drug development examples and clinical applications.