BSI-992/902

OBI-992 (also referred to as BSI-992) is a TROP2-targeted antibody-drug conjugate (ADC) carrying a potent topoisomerase I inhibitor payload. It features a drug-to-antibody ratio of 4 (DAR 4) and is conjugated via a thiol-containing, hydrophilic, and enzymatically cleavable linker. OBI-992 remains stable in systemic circulation, effectively delivering the cytotoxic payload directly to TROP2-expressing tumor cells to induce tumor cell death while avoiding off-target toxicities. TROP2 is highly expressed across a broad range of solid tumors but shows minimal to no expression in normal tissues, making it an ideal therapeutic target for cancer therapy. OBI holds the global commercial rights for this project outside of Mainland China.

Compared to benchmark TROP2 ADCs, OBI-992 exhibits a favorable and distinct pharmacokinetic (PK) profile, characterized by exceptional stability in blood circulation, prolonged tumor exposure, and durable antitumor activity across multiple cancer models. Its safety profile has been validated in repeat-dose toxicity studies in mice. Since December 2021, OBI has licensed the amino acid sequence of this TROP2-targeted antibody from Biosion, securing exclusive global development and commercialization rights outside of the Greater China region.