Antengene Corporation Limited (Antengene) has entered a global clinical collaboration with MSD (Merck & Co., Inc.) to evaluate the combination of ATG-022 and MSD’s anti-PD-1 therapy, KEYTRUDA (pembrolizumab), in patients with advanced solid tumors.

ATG-022 is a CLDN18.2-targeting antibody-drug conjugate (ADC). Data support meaningful efficacy across all levels of Claudin 18.2 expression in gastric cancer, including high, low, and ultra-low expressors.

Antengene presented the latest data from its Phase I/II CLINCH study at the 2025 American Society of Clinical Oncology Gastrointestinal Cancers Symposium.

Results showed an objective response rate (ORR) of 42.9% and a disease control rate (DCR) of 95.2% in patients with moderate to high CLDN18.2 expression (IHC 2+ ≥ 20%). 

Additionally, the study demonstrated an ORR of 30.0% and a DCR of 50.0% in patients with low CLDN18.2 expression (IHC 2+ < 20%).

ATG-022 also exhibited a favorable safety profile and extended treatment durations, with no observed cases of ophthalmological or neurological toxicities, nor interstitial lung disease.

The U.S. FDA has awarded Orphan Drug Designations to ATG-022, for gastric and pancreatic cancers.