Fosun Pharma’s Anti-HER2 Antibody HLX22 Receives FDA Orphan Drug Designation for Gastric Cancer
By Thomas Yuan, Health and Biotechnology Correspondent

SHANGHAI — On March 19, Fosun Pharma announced that its innovative anti-HER2 monoclonal antibody, HLX22, has been granted orphan drug status by the U.S. Food and Drug Administration for the treatment of gastric cancer, marking a significant milestone in the global development of targeted therapies for aggressive gastrointestinal malignancies.

HLX22 is currently undergoing an international Phase 3 multicenter clinical trial (HLX22-GC-301), in combination with trastuzumab and chemotherapy, as a first-line treatment for HER2-positive advanced gastric cancer. The trial has received IND approvals from regulatory agencies in China, the United States, Japan, and Australia, and the first patient has already been dosed globally.

Addressing a High-Mortality Cancer with Unmet Needs

Gastric cancer is often diagnosed at an advanced stage due to subtle early symptoms, contributing to a dismal 5-year survival rate of just 6%, according to published clinical literature. Despite recent advances using HER2-targeted therapies and immune checkpoint inhibitors, treatment response remains highly variable due to the molecular heterogeneity of gastric cancer. As such, there is a pressing need for more effective and precise biologic therapies.

A Novel Mechanism for HER2 Blockade

HLX22 is designed to target a unique epitope on domain IV of HER2, distinct from that of trastuzumab, enabling dual binding and synergistic anti-tumor activity. The antibody facilitates the internalization and degradation of HER2 dimers, including both HER2 homodimers and HER2/EGFR heterodimers, which are implicated in cancer cell proliferation and resistance.

This mechanism allows HLX22 to deliver a stronger receptor blockade, potentially overcoming limitations of traditional HER2 therapies. Combined with trastuzumab, the drug is positioned as a next-generation biologic for HER2-positive cancers with high resistance profiles.

Promising Phase 2 Data and Global Trial Expansion

In a Phase 2 trial (HLX22-GC-201), HLX22 combined with Hanqu You (biosimilar trastuzumab) and chemotherapy demonstrated improved survival outcomes and enhanced tumor response in first-line treatment of HER2-positive gastric and gastroesophageal junction (G/GEJ) cancers. The combination was well-tolerated, with manageable safety profiles.

These results have generated optimism that HLX22 could reshape the standard of care for advanced HER2-positive gastric cancer, where current options remain limited.

Global Strategy and Future Outlook

The FDA’s orphan drug designation grants HLX22 regulatory incentives including market exclusivity, tax credits, and accelerated review, further supporting Fosun Pharma’s strategy to globalize its biopharmaceutical innovation pipeline.

As HLX22 advances into Phase 3, it joins a growing field of next-generation targeted therapies aiming to address complex cancers with molecular precision. For Fosun, it reinforces the company’s position in global oncology drug development, while offering hope to patients facing one of the most lethal forms of gastrointestinal cancer.

With further clinical validation, HLX22 may emerge not only as a transformative treatment option, but also as a benchmark for combination biologics in future anti-HER2 cancer strategies.