AbClon announced on May 27 that AC101 (Henlius code name HLX22), an antibody therapy out-licensed to China's Henlius Biotech, has been granted Orphan Drug Designation (ODD) by the European Commission (EC) for the treatment of gastric cancer.

With this designation, HLX22 has become the world's first anti-HER2 targeted therapy to obtain ODD from both the U.S. Food and Drug Administration (FDA) in March and the European EC in May. This ODD is a significant step towards faster commercialization, establishing a strong basis for an innovative treatment expected to show superior efficacy in gastric cancer compared to existing therapies.

The ODD was granted based on a positive assessment from the Committee for Orphan Medicinal Products (COMP) under the European Medicines Agency (EMA). The EC determined that HLX22 meets the requirements for an orphan medicinal product, targeting a life-threatening or severely debilitating condition.

As a result, HLX22 will secure various incentives throughout its research, development, and approval processes. These include:

• Assistance with clinical trial design

• Centralized marketing authorization procedures

• 10 years of market exclusivity protection after marketing approval

• Reduced regulatory fees

Globally, gastric cancer remains a serious public health challenge. According to GLOBOCAN 2022 by the International Agency for Research on Cancer, there were approximately 1 million new gastric cancer diagnoses and over 660,000 deaths in 2022. The majority of patients are diagnosed at an advanced stage, leading to a poor prognosis.

Specifically, HER2-positive gastric cancer accounts for 12-23% of all gastric cancer patients and is reported to have a worse prognosis than HER2-negative patients.

The current standard first-line treatment for HER2-positive metastatic gastric cancer involves a combination of trastuzumab and chemotherapy, occasionally supplemented with immunotherapy. However, the therapeutic outcomes remain limited, indicating a significant need for improvement. AbClon explains that HLX22 is drawing attention as a new therapeutic alternative.

HLX22 is being developed as a first-line treatment for patients with HER2-positive metastatic gastric cancer and gastroesophageal junction (GC/GEJC) cancer. A global Phase 3 clinical trial (HLX22-GC-301), combining HLX22 with trastuzumab and chemotherapy, is currently underway with active global development.

This Phase 3 trial has received Investigational New Drug (IND) approvals in key countries, including China, the U.S., Japan, Australia, South Korea, and Germany. To date, the first patients have already been dosed in China, Japan, and Australia.

According to Henlius's published Phase 2 clinical data on HLX22 in combination with the trastuzumab biosimilar Hanquyou® (HERCESSI™/Zercepac®), a significant improvement in survival rates and anti-tumor efficacy was observed compared to existing treatments, while maintaining a favorable safety profile. The Phase 3 clinical trial design and subsequent updates are also scheduled to be presented at this week's ASCO 2025 annual meeting.

Beyond gastric cancer, HLX22 is also being explored for other cancer types with significantly larger patient populations. Currently, HLX22 is undergoing a Phase 2 clinical trial in China, in combination with trastuzumab deruxtecan (T-DXd), for patients with HER2-low and hormone receptor (HR)-positive locally advanced or metastatic breast cancer. The first patient has already been dosed in this trial as well.

AbClon stated, "The European ODD designation will further accelerate HLX22's global clinical development and commercialization." They added that "Henlius projects HLX22's peak annual sales to reach $10 billion, which would generate over 700 billion Korean Won in royalties for AbClon."