Commercial-stage biotech company Antengene Corporation Limited (SEHK:6996) announced on Thursday that the first patient has been dosed in China in the Phase I ATTRACT study evaluating ATG-201, Antengene's proprietary CD19 x CD3 bispecific T-cell engager antibody (TCE) in adult patients with B cell-mediated autoimmune diseases.

The Phase I ATTRACT study is being conducted in China and Australia. ATG-201 has obtained approval from the Human Research Ethics Committee (HREC) in Australia, and completed the Clinical Trial Notification (CTN) process with the Therapeutic Goods Administration (TGA).

ATG-201 is a CD19 targeting bispecific TCE incorporating steric hindrance masking technology, designed to eliminate CD19-expressing B cells. This bispecific interaction with T and B cells through CD3 and CD19 has demonstrated potential in treating B cell-mediated diseases by leveraging the body's own immune system for precise and potent action.

Primary objectives of the Phase I study are to evaluate the safety and tolerability of ATG-201 and to determine the recommended Phase II dose (RP2D). Secondary objectives include evaluating the pharmacokinetic (PK) and pharmacodynamic (PD) profiles, immunogenicity, and preliminary efficacy of ATG-201.

Antengene and Belgium-based biopharmaceutical company UCB (EBR:UCB) have entered into an agreement that grants UCB worldwide exclusive rights to further develop, manufacture, and commercialise ATG-201, and access to its associated manufacturing technology in relation to ATG-201.