Overexpression of B7-H3 as an opportunity for targeted therapy in head and neck cancers.

Head and neck cancers (HNCs) are the sixth most common type of cancer in the world. Despite the development of refined surgical techniques and precise targeted radiation, patients with HNCs have a dismal prognosis. Here, we examine the expression profile of B7-H3 in HNCs and verify whether B7-H3 can serve as a novel therapeutic target for HNCs via anti-B7-H3×CD3 bispecific antibodies (biAbs). We analyzed the expression level of B7-H3 in 274 HNC samples and evaluated the association between B7-H3 expression and clinicopathological parameters. Anti-B7-H3×CD3 biAbs were constructed, and the efficacy of these biAbs in targeting HNCs was assessed in vitro and in vivo. As a result, high expression of B7-H3 was detected in 66.1% of clinical HNC samples and was correlated with poor survival. Specific antitumor effects of anti-B7-H3×CD3 biAbs were confirmed in vitro using HNC cell lines. In xenograft HNC mouse model, anti-B7-H3×CD3 biAbs delayed tumor growth and prolonged survival. In conclusion, B7-H3 is frequently overexpressed in HNCs and could be a promising therapeutic target for biAb therapy.