FDA Grants Orphan Drug Designation to HanchorBio's HCB101 for Gastric Cancer Treatment
The U.S. FDA granted orphan drug designation to HCB101, a next-generation immunotherapy from HanchorBio, for treating gastric cancer including HER2-positive and HER2-negative subtypes.
HanchorBio, Inc., a global clinical-stage biotechnology company advancing next-generation immunotherapies for oncology and autoimmune diseases, announced that the U.S. Food and Drug Administration (FDA) granted Orphan Drug Designation (ODD) to HCB101 for the treatment of gastric cancer. The designation covers gastric cancer broadly, including advanced gastric adenocarcinoma in both HER2-positive and HER2-negative subtypes.
This designation marks the first FDA Orphan Drug Designation for HanchorBio, representing a significant regulatory milestone for the company and further validating its strategy of advancing differentiated immunotherapies in areas of high unmet medical need. This milestone underscores the significant unmet medical need in gastric cancer and provides important regulatory support for the continued clinical development of HCB101 in this patient population.
HCB101 is a next-generation CD47–SIRPα pathway inhibitor, engineered as an affinity-optimized and toxicity-mitigated SIRPα-IgG4 Fc fusion protein. The molecule is designed to restore macrophage-mediated phagocytosis and enhance antigen presentation while minimizing the hematologic toxicities that have historically limited earlier CD47-targeting approaches, enabling rational combination with established standards of care.
The company's founder, chairman, and CEO stated that gastric cancer remains an area of profound unmet medical need, and this designation reinforces the company's commitment to developing differentiated immunotherapies that can meaningfully improve outcomes for patients. The designation strengthens HCB101's profile as a globally relevant asset and represents a strategically important step as the company advances the program toward U.S. and international development. It further supports ongoing engagement with multinational partners as the company explores collaboration and licensing opportunities for HCB101 and its broader immunotherapy pipeline.
Gastric cancer is a rare disease in the United States, with prevalence well below the FDA's statutory threshold for orphan designation. Despite advances in targeted therapy and immune checkpoint inhibition, outcomes, particularly in the second-line setting, remain poor, with limited durability of response and substantial treatment-related toxicity.
HCB101 is currently being evaluated in multiple ongoing clinical studies, including a Phase 1b/2a trial (NCT06771622) assessing HCB101 in combination with ramucirumab and paclitaxel in second-line advanced gastric cancer. Early clinical findings have demonstrated promising antitumor activity with a safety profile consistent with the molecule's differentiated design.
The company's president and chief medical officer noted that HCB101's IgG4-based SIRPα-Fc design was intentionally selected to support repeated dosing and combination strategies as an innate immune checkpoint backbone in solid tumors. In a second-line gastric cancer setting, where standard regimens offer limited durability, the depth of tumor shrinkage and consistency of response observed to date, while remaining compatible with standard ramucirumab-paclitaxel administration, support the continued global advancement of HCB101 for patients with significant unmet need.
Orphan Drug Designation provides certain development incentives, including eligibility for tax credits on qualified clinical trial expenses, exemption from FDA user fees, and the potential for seven years of market exclusivity upon approval in the United States.
HanchorBio plans to continue advancing HCB101 through global clinical development while exploring its potential as a backbone immunotherapy across multiple solid tumor indications.
HCB101 is a rationally engineered SIRPα–IgG4 Fc fusion protein developed on HanchorBio's FBDB platform to selectively block the CD47–SIRPα innate immune checkpoint while minimizing hematologic toxicity. Unlike earlier anti-CD47 approaches, HCB101 is designed to preserve macrophage-mediated antitumor activity while reducing binding to red blood cells, a limitation that historically constrained the clinical utility of CD47-directed therapies.
HCB101 was engineered using AI-assisted structural modeling to achieve differentiated binding to CD47 on cancer cells while maintaining low affinity for CD47 on red blood cells. Its safety profile, receptor occupancy characteristics, and pharmacologic properties are designed to support integration with established oncology regimens without disrupting standard dosing, safety expectations, or clinical workflows.