Shanghai – November 06, 2026 -- Antengene Corporation Limited (SEHK: 6996.HK) has dosed the first patient in China in the Phase I ATTRACT study of ATG-201, its CD19 x CD3 bispecific T-cell engager (TCE) for adult patients with B cell-mediated autoimmune diseases. UCB holds worldwide exclusive rights to develop, manufacture and commercialize the asset.
UCB holds global rights while Antengene runs Phase I in China and Australia
Under the agreement, UCB also gains access to the manufacturing technology associated with ATG-201. Antengene remains responsible for conducting the Phase I trials in China and Australia.
The Australian arm has cleared its regulatory steps. ATG-201 has obtained approval from the Human Research Ethics Committee (HREC) and completed the Clinical Trial Notification (CTN) process with the Therapeutic Goods Administration (TGA).
ATTRACT study splits into dose escalation and dose expansion parts
Prof. Zhanguo Li of Peking University People's Hospital is principal investigator. Part I covers dose escalation and Part II covers dose expansion.
The primary objectives are to evaluate safety and tolerability and to determine the recommended Phase II dose (RP2D). Secondary objectives cover pharmacokinetic and pharmacodynamic profiles, immunogenicity and preliminary efficacy.
Steric hindrance masking underpins ATG-201's B-cell depletion approach
ATG-201 uses steric hindrance masking technology and is designed to eliminate CD19-expressing B cells by engaging T cells through CD3. It was built on Antengene's proprietary AnTenGager platform, a TCE 2.0 platform that uses proprietary CD3 sequences with fast on/off kinetics to minimize cytokine release syndrome (CRS).
Li cited low remission rates, high relapse risk and long-term safety concerns in refractory B cell-mediated autoimmune disease, and called the first dosing an "important milestone."
ATG-201 is one of seven TCE programs on the AnTenGager platform
ATG-201 is the only autoimmune program on the platform listed with a partner. ATG-106, targeting CDH6 x CD3 in ovarian and kidney cancer, is partnered with K2 Therapeutics, established by MPM BioImpact. The remaining oncology programs include ATG-112, ATG-110, ATG-021, ATG-102 and ATG-107.