Antengene-B (06996) saw its shares climb more than 9% in Hong Kong trading, with the stock last up 9.06% at HK$3.61, on turnover of HK$3.84 million.

According to the company's official WeChat announcement on September 21, Antengene-B confirmed that the first patient has been dosed in China for the pivotal Phase III CLINCH-3 study, which evaluates the CLDN18.2-targeted antibody-drug conjugate (ADC) ATG-022 as a treatment for CLDN18.2-positive advanced gastric or gastroesophageal junction adenocarcinoma.

ATG-022 had previously received Breakthrough Therapy Designation from the Center for Drug Evaluation (CDE) of China's National Medical Products Administration (NMPA). This designation has facilitated more efficient communication with the CDE, laying a solid foundation for the rapid advancement of the CLINCH-3 study.

The trial has been initiated in China, where the first patient has already been dosed. Antengene-B plans to expand the study into a multi-regional clinical trial (MRCT), with the goal of generating robust clinical evidence to support the future regulatory submission and marketing approval of ATG-022 as monotherapy for CLDN18.2-positive advanced gastric or gastroesophageal junction adenocarcinoma.