FDA Grants Orphan Drug Designation to HCB101 in HER2+/– Gastric Cancer

The FDA has granted orphan drug designation to HCB101 for the treatment of gastric cancer, including advanced gastric adenocarcinoma across both HER2-positive and HER2-negative subtypes, according to a press release from HanchorBio, Inc.¹

The regulatory milestone follows early-phase data indicating that the next-generation SIRPα-Fc pathway inhibitor protein may overcome the hematological toxicity limitations of prior CD47-directed therapies. Most recently, data from the ongoing phase 1b/2a HCB101-201 trial (NCT06771622) were presented at the 2026 ASCO Gastrointestinal Cancers Symposium.²

“Receiving our first FDA orphan drug designation is a major milestone for HanchorBio and important validation of our scientific, regulatory, and development strategy,” stated Scott Liu, PhD, founder, chairman, and chief executive officer of HanchorBio, in the press release.¹ “Gastric cancer remains an area of profound unmet medical need, and this designation reinforces our commitment to developing differentiated immunotherapies that can meaningfully improve outcomes for patients. This designation strengthens HCB101's profile as a globally relevant asset and represents a strategically important step as we advance the program toward U.S. and international development. It further supports our ongoing engagement with multinational partners as we explore collaboration and licensing opportunities for HCB101 and our broader immunotherapy pipeline.”

Clinical Efficacy

Findings the HCB101-201 trial demonstrated significant antitumor activity when HCB101 was combined with standard-of-care ramucirumab (Cyramza) and paclitaxel in the second-line setting. Among 13 efficacy-evaluable patients with advanced gastric adenocarcinoma who had progressed after first-line therapy, the combination produced an overall objective response rate (ORR) of 0% at the 2.56 mg/kg and 100% at the 5.12 mg/kg and 8 mg/kg dose levels. Across all doses, the disease control rate (DCR) was 100%.

The efficacy signals were particularly pronounced in the mid-dose cohorts (5.12 mg/kg and 8.0 mg/kg), where 8 of 10 patients experienced a partial response. In the 5.12 mg/kg cohort (n = 3), the mean tumor shrinkage was 42.6%, and in the 8 mg/kg cohort (n = 7), it was 37.2%. Among patients who received 2.56 mg/kg, the mean tumor shrinkage was 6.0%. Notably, the maximum tumor reduction across all patients was 78.2%, which was observed in 1 patient in the 8 mg/kg cohort.

Among the 5 patients with first line gastric cancer who were enrolled as of December 19, 2025, 3 were efficacy evaluable at the 8 mg/kg dose level. Of those 3 patients, 2 achieved partial responses and 1 stable disease.

Trial Breakdown

The HCB101-201 study is a multicenter, open-label, dose-escalation and expansion trial designed to evaluate the safety and preliminary efficacy of HCB101 in combination with: HER2-targeted therapy in first line HER2-positive gastric cancer, or with ramucirumab plus paclitaxel in second line gastric cancer.

HCB101 was administered as a weekly intravenous infusion in a 3+3 dose escalation schedule, with doses ranging from 2.56 mg/kg to 12 mg/kg. The regimen included ramucirumab at 8 mg/kg on days 1 and 15, and paclitaxel at 80 mg/m² on days 1, 8, and 15 of each 28-day cycle. The primary end point of the trial was to identify the maximum tolerated dose and the recommended phase 2 dose. Secondary end points included ORR, progression-free survival, duration of response, overall survival, and pharmacokinetics.

Eligible participants in this cohort of the trial include adults 18 years or older with histologically or cytologically confirmed advanced or metastatic gastric or gastroesophageal junction adenocarcinoma. Patients were required to have an ECOG performance status of 0 or 1.

Safety Profile

Among patients with second-line gastric cancer, a total of 313 adverse events (AEs) were reported, of which 256 were related to HCB101; 84% of those were grade 1 or 2. The most common AEs related to HCB101 were white blood cell count decreased (63 events) and anemia (15 events). The one dose limiting toxicity was grade 4 thrombocytopenia, which occurred at the 8 mg/kg dose level; a total of 4 grade 3 or higher HCB101-related serious AEs occurred and were thrombocytopenia, neutropenia, and leukopenia. Toxicities were managed with standard interventions.

Among patients with first line gastric cancer, a total of 51 adverse events were reported, of which 27 were grade 1 or 2 AEs related to HCB101.

References

1. HanchorBio receives FDA orphan drug designation for HCB101 in gastric cancer. News release. HanchorBio, Inc. February 13, 2026. Accessed February 13, 2026. https://tinyurl.com/ddevvnj2
2. Yu LA, Ning F, Zhou Z, et al. Dose-dependent antitumor activity of HCB101 plus ramucirumab and paclitaxel in previously treated gastric cancer. Poster presented at: 2026 ASCO Gastrointestinal Cancers Symposium; January 22-24, 2026; San Francisco, CA. Abstract 372.