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.