China NMPA Clears InnoCare's Bispecific ADC ICP-B381 for Clinical Trials
核心洞察
China's NMPA Center for Drug Evaluation has approved InnoCare Pharma (搜索)'s IND application for ICP-B381 (搜索), a bispecific antibody-drug conjugate targeting PSMA (搜索) and STEAP1 (搜索).
The dual-targeting design aims to counter tumor antigen heterogeneity, a limitation of single-antigen ADCs in which low- or absent-target cell subpopulations drive resistance.
ICP-B381 (搜索) is InnoCare's first bispecific ADC and third ADC overall to enter clinical development, using a humanized bispecific antibody with an irreversible linker.
China's National Medical Products Administration (搜索) (NMPA), through its Center for Drug Evaluation (CDE), has cleared InnoCare Pharma (搜索) (HKSE: 9969) to begin clinical testing of ICP-B381 (搜索), a bispecific antibody-drug conjugate (ADC) that simultaneously engages two prostate cancer (搜索)-associated antigens: prostate-specific membrane antigen (PSMA (搜索)) and six-transmembrane epithelial antigen of the prostate 1 (STEAP1 (搜索)). The investigational new drug application covers the treatment of solid tumors, with prostate cancer as a primary focus.
The dual-targeting approach is designed to address a limitation common to single-antigen ADCs — tumor antigen heterogeneity, in which subpopulations of cells with low or absent target expression can survive and drive resistance. By engaging both PSMA (搜索) and STEAP1 (搜索) at once, ICP-B381 (搜索) is intended to address antigen heterogeneity and potentially reduce tumor escape associated with low or lost target expression. According to InnoCare, both targets are significantly overexpressed in prostate cancer (搜索) cells with limited expression in normal tissue.
ICP-B381 (搜索) is built on InnoCare's proprietary ADC platform and comprises a humanized anti-PSMA (搜索)/STEAP1 (搜索) bispecific antibody conjugated to a proprietary cytotoxic payload via what the company described as a next-generation irreversible linker; the specific payload class has not been disclosed. The candidate is InnoCare's first bispecific ADC to enter clinical development and its third ADC overall to reach this stage.