ADC platform

Bio-Thera has independently developed and owned a new ADC technology platform, using cleavable linkers to couple toxic small molecule topoisomerase I inhibitors with antibodies. The payload has strong cell membrane permeability. It can release and kill nearby cancer cells after ADC kills cancer cells, produce bystander effect, and effectively overcome the heterogeneity of tumor cells. At the same time, the new platform has good stability and safety, and the release of payload in plasma is extremely low, reducing the risk of off-target toxicity. Multiple ADC candidates developed by the new platform have demonstrated potent anti-tumor activity in in vitro and in vivo pharmacological studies, enabling the development of potential "best in class" antibody-drug conjugate for targeted therapy.

ADCC platform

Our ADCC-enhanced antibody platform is mainly based on gene editing technology to knock-out the FUT8 protein in CHO-K1 host cells for producing antibodies, and the antibodies produced by the engineered host cells are completely free fucose. Since the fucose in the Fc region of the antibody hinders the binding of the antibody to FcγRIIIa (CD16a), the afucosylated Fc region increases the affinity of the antibody to FcγRIIIa, so the afucosylated antibody can recruit more effector cells to be to the tumor site to enhance the effect of ADCC (one of the main mechanisms of therapeutic antibodies in cancer treatment). We have currently developed six ADCC-enhanced antibody drug candidates, all of which are in clinical development stage.