HanchorBio, a clinical-stage biotechnology company focused on next-generation immunotherapies for oncology and autoimmune diseases, has received Orphan Drug Designation (ODD) from the U.S. Food and Drug Administration (FDA) for HCB101 in the treatment of gastric cancer.

The designation applies broadly to gastric cancer, including advanced gastric adenocarcinoma in both HER2-positive and HER2-negative subtypes. It marks the company’s first FDA Orphan Drug Designation and represents a significant regulatory milestone, reinforcing HanchorBio’s strategy of advancing differentiated immunotherapies in areas of high unmet medical need.

HCB101 is a next-generation inhibitor of the CD47–SIRPα pathway, engineered as an affinity-optimised and toxicity-mitigated SIRPα-IgG4 Fc fusion protein. The therapy is designed to restore macrophage-mediated phagocytosis and enhance antigen presentation while minimising hematologic toxicities that have historically limited earlier CD47-targeted approaches. Its structure supports rational combination with established standards of care.

Scott Liu, PhD, Founder, Chairman and CEO of HanchorBio, said the designation validates the company’s scientific and regulatory strategy. He noted that gastric cancer remains an area of profound unmet medical need and added that the decision strengthens HCB101’s profile as a globally relevant asset as the company advances the programme across U.S. and international markets while exploring collaboration and licensing opportunities.

Gastric cancer is considered a rare disease in the United States, with prevalence below the FDA’s statutory threshold for orphan designation. Despite advances in targeted therapies and immune checkpoint inhibitors, outcomes—particularly in second-line treatment remain poor, with limited durability of response and significant treatment-related toxicity.

HCB101 is currently being evaluated in several ongoing clinical studies, including a Phase Ib/IIa trial assessing the therapy in combination with ramucirumab and paclitaxel in second-line advanced gastric cancer. Early findings have demonstrated encouraging antitumor activity and a safety profile aligned with the molecule’s differentiated design.

Alvin Luk, PhD, MBA, CCRA, President and Chief Medical Officer (Group) and CEO (U.S.A.) of HanchorBio, said the FDA’s decision underscores both the seriousness of gastric cancer and the clinical rationale behind HCB101’s development. He added that the molecule’s IgG4-based SIRPα-Fc design was selected to support repeated dosing and combination strategies as an innate immune checkpoint backbone, with early data showing meaningful tumor shrinkage while remaining compatible with standard ramucirumab-paclitaxel administration.

Orphan Drug Designation provides development incentives, including tax credits for qualified clinical trial expenses, exemption from certain FDA user fees, and the potential for seven years of market exclusivity upon approval in the United States.

The company plans to continue advancing HCB101 through global clinical development while evaluating its broader potential as a backbone immunotherapy across multiple solid tumor and hematologic malignancy indications.

HCB101 was developed using HanchorBio’s proprietary FBDB platform and AI-assisted structural modeling to selectively block the CD47–SIRPα innate immune checkpoint. Unlike earlier anti-CD47 therapies, the molecule is engineered to reduce binding to red blood cells, a limitation that has constrained previous approaches, while maintaining macrophage-mediated antitumor activity.

Across ongoing clinical and translational studies, HCB101 has demonstrated consistent target engagement and early antitumor activity as both a monotherapy and in combination regimens, positioning it as a differentiated innate immune checkpoint candidate with broad potential across oncology indications.