Discovery of novel antibody-drug conjugates bearing tissue protease specific linker with both anti-angiogenic and strong cytotoxic effects.

Bevacizumab is an FDA-approved class of monoclonal antibodies used to inhibit angiogenesis and promote normalization of blood vessels. It is usually combined with chemotherapeutic agents to treat a variety of solid tumors. However, the whole-body toxicities and toxicity associated with chemotherapy greatly limit the clinical use of this combination therapy. Antibody-drug conjugates (ADCs) couple monoclonal antibodies to cytotoxic molecules via a linker, utilizing the high specificity of monoclonal antibodies to tumor surface antigens to act as a "biological missile" to deliver chemotherapeutic drugs to the tumor site. Herein, we designed a bevacizumab-based ADC, Bevacizumab Vedotin, conjugating bevacizumab to the microtubulin inhibitor MMAE via a tissue protease-specific linker. Biological studies showed strong stability and good tumor cell targeting of our constructed ADCs; rapid drug release was achieved in the presence of exogenous histone protease B. In addition, Bevacizumab Vedotin exhibited good anti-proliferative, apoptosis-promoting and cell cycle-stalling effects on glioma (U87), hepatocellular carcinoma (HepG2), and breast cancer (MCF-7) cell lines. Further in vitro assays demonstrated the enhanced anti-migration activity against MCF-7, potent anti-angiogenic effects, and blockade of the VEGF/VEGFR pathway of Bevacizumab Vedotin.