Chinese biotech company Antengene Corporation Limited (SEHK:6996) announced on Wednesday that, following review by the Center for Drug Evaluation (CDE) of China's National Medical Products Administration (NMPA), the company has received CDE endorsement to conduct the pivotal Phase III CLINCH-3 study of ATG-022, a Claudin 18.2 (CLDN18.2) antibody-drug conjugate (ADC), for the treatment of CLDN18.2+ advanced gastric or gastroesophageal junction (GEJ) adenocarcinoma.

The study is expected to be initiated in China first, and is planned as a multi-regional clinical trial (MRCT).

The randomised, controlled, open-label, multicentre Phase III clinical study is designed to evaluate the efficacy and safety of ATG-022 versus treatment of investigator's choice in patients with CLDN18.2+ advanced gastric or GEJ adenocarcinoma. Primary endpoints are progression-free survival as assessed by independent review committee and overall survival. Secondary endpoints include objective response rate, duration of response, disease control rate, safety, and other measures.

Initiation of this pivotal study is supported by encouraging results from the Phase I/II CLINCH study, which showed that ATG-022, as monotherapy, demonstrated a differentiated efficacy and safety profile in patients with advanced gastric or GEJ adenocarcinoma. The company says that together with its robust anti-tumour activity, encouraging survival outcomes and favourable tolerability, these data position ATG-022 as a potential best-in-disease therapy for gastric cancer or GEJ adenocarcinoma.

Antengene says that it will continue to advance a comprehensive clinical development strategy for ATG-022 across multiple settings, including its pivotal monotherapy study in advanced gastric or GEJ adenocarcinoma, ongoing combination studies with anti-PD-1 therapy and chemotherapy in the 1L gastric cancer setting, and further exploration in other CLDN18.2+ solid tumours, including tumour types beyond the digestive system where encouraging efficacy signals with confirmed tumour responses have been observed.