The board of directors of Shanghai Henlius Biotech, Inc. announced that, recently, application for the phase 3 clinical trial of HLX22 (anti-human epidermal growth factor receptor-2 (HER2) humanized monoclonal antibody injection) ("HLX22") in combination with Trastuzumab and chemotherapy as the first-line treatment of HER2 positive advanced gastric cancer has been approved by the United States Food and Drug Administration (FDA). HLX22 is an innovative anti-HER2 monoclonal antibody introduced from AbClon, Inc. and subsequently self-developed by the Company with potential indications including gastric cancer, breast cancer and other solid tumours, which has completed the phase 1 clinical trial for the treatment of HER2 overexpressing advanced solid tumors in mainland China (excluding Hong Kong, Macau and Taiwan regions, the same as below). Both HLX22 and Trastuzumab are anti-HER2 monoclonal antibodies that bind to the domain IV of HER2, but the epitopes they bind to are different, which allows HLX22 and Trastuzumab to simultaneously bind to the domain IV of HER2 to induce stronger HER2 receptor blockade.

Results of pre-clinical studies indicate that the combination of HLX22 and Trastuzumab has a synergistic anti-tumor effect, better than HLX22 or Trastuzumab as a single antibody. As of 6 May 2024, a phase 2 clinical trial of HLX22 in combination with Trastuzumab and chemotherapy as the first-line treatment of HER2-positive locally advanced/metastatic gastric cancer (GC) is underway in mainland China. In October 2022, the application for the phase 2 clinical trial of HLX22 in combination with HANSIZHUANG (serplulimab injection) and the standard therapy (Trastuzumab and chemotherapy) as the first-line treatment for locally advanced/metastatic gastric cancer (GC) has been approved by the National Medical Products Administration.

As of 6 May 2024, no marketing approval has been obtained for similar combination therapy for the treatment of gastric cancer worldwide. The Company cannot guarantee the successful development and commercialization of HLX22. Shareholders and potential investors of the Company are advised to exercise caution when dealing in the shares of the Company.