Preclinical and clinical data with bispecific antibodies recruiting myeloid effector cells for tumor therapy.

Bispecific antibodies constitute a novel approach to improve antibody efficacy. In vitro, constructs to recruit myeloid effector cells have been extensively investigated, and first animal data in human Fc receptor transgenic mice confirmed their promising therapeutic potential. Clinical experience with these constructs demonstrated acceptable toxicity, and support therapeutic efficacy in subgroups of patients. However, limited availability, unacceptable immunogenicity, and unfavorable pharmacokinetics of bispecific compared to conventional antibodies often hampered clinical studies. As solutions to these problems are available today, bispecific antibodies hold promise to improve therapeutic efficacy of antibody-based approaches in the near future.