Shanghai Henlius Biotech, Inc. (2696.HK) announced that the U.S. Food and Drug Administration (FDA) has granted Orphan Drug Designation (ODD) for HLX22, the company's innovative anti-HER2 monoclonal antibody (mAb) for the treatment of gastric cancer.

Receiving an Orphan Drug Designation for HLX22 recognizes its potential to treat patients with gastric cancer and marks another milestone for HLX22, following the initiation of its multicenter phase 3 clinical trials in multiple countries and regions worldwide, and signifies a crucial step forward in its global presence.

Until now, gastric cancer still constitutes a major global health problem. According to GLOBOCAN 2022, there were around 1 million new cases and over 660 thousand new deaths of gastric cancer in 2022 globally. Gastric cancer is often diagnosed at an advanced stage, with a poor prognosis and a 5-year relative survival rate of only 6%. Despite significant advancements in targeted therapies, such as anti-HER2 agents, and immune checkpoint inhibitors (anti-PD-1/PD-L1 mAbs) for gastric cancer treatment in recent years, the disease's high molecular heterogeneity leads to markedly varied responses to chemotherapy, targeted therapy, and immunotherapy across different subtypes.

HLX22, an innovative anti-HER2 mAb, can bind to HER2 extracellular subdomain IV at a binding site different from that of trastuzumab via differentiated molecular design and mechanism of action, which allows simultaneous binding of HLX22 and trastuzumab to HER2 dimers (HER2 homodimer and HER2/EGFR heterodimer) on tumour cell surface, thereby promoting the internalization and HER2 dimer degradation. The phase 2 clinical data on the combination of HLX22 and HANQUYOU (trastuzumab, trade name: HERCESSI? in the U.S., Zercepac? in Europe) demonstrate that the addition of HLX22 to trastuzumab plus chemotherapy significantly improves survival and anti-tumour efficacy in first-line treatment of HER2-positive gastric/gastroesophageal junction cancer (GC/GEJC) patients, with manageable safety profiles，expected to redefine the first-line standard treatment for advanced gastric cancer. At present, the Investigational New Drug (IND) applications for HLX22-GC-301, a phase 3 clinical study aims to evaluate the efficacy and safety of HLX22 in combination with trastuzumab and chemotherapy for the first-line treatment of patients with HER2-positive metastatic GC/GEJC have been approved in China, the U.S, Japan and Australia, etc. This international study has been initiated in multiple countries and regions worldwide and has completed its first patient dosing globally.