HanchorBio Reports Preliminary First-Line HER2+ Gastric Cancer Data for HCB101, Demonstrating 83.3% ORR

HanchorBio Reports Preliminary First-Line HER2+ Gastric Cancer Data for HCB101, Demonstrating 83.3% ORR

Early clinical observations show deep tumor reductions across dose levels, supporting continued development in combination settings

[Taipei, Shanghai, San Francisco | April 1, 2026] – HanchorBio, Inc. (TPEx: 7827), a global clinical-stage biotechnology company advancing next-generation immunotherapies for oncology and autoimmune diseases, today reported preliminary clinical observations from its ongoing Phase 1b/2a study evaluating HCB101-based combination therapy in first-line HER2-positive gastric cancer.

Among 6 efficacy-evaluable patients treated across multiple dose levels (5.12, 8, and 12 mg/kg), 5 achieved confirmed partial responses (PRs), yielding an objective response rate (ORR) of 83.3%. The disease control rate (DCR) was 100%. Tumor reductions were observed in all evaluable patients, with multiple cases demonstrating deep responses ranging from -30% to -65%. Responses have been observed across dose levels, with patient follow-up ongoing.

While the dataset remains early and limited in size, the observed ORR compares favorably with historical benchmarks for standard-of-care first-line HER2-positive gastric cancer regimens, including studies such as ToGA, JACOB, and KEYNOTE-811, where ORR have generally ranged from approximately 50% to 60%, depending on the regimen and patient population.

The inclusion of dual HER2-directed antibodies (trastuzumab and pertuzumab) in the combination regimen reflects a mechanism-based strategy. Both antibodies provide complementary HER2 epitope coverage and enhance tumor cell opsonization, increasing susceptibility to Fc-mediated effector functions. In the presence of CD47-SIRPα blockade, this dual-antibody configuration may further augment macrophage-mediated phagocytosis and antigen presentation, supporting both innate and downstream adaptive immune activation. This approach is consistent with the design objective of HCB101 to serve as an enabling agent in combination with antibody-based regimens.

Dr. Scott Liu, Founder and Chairman of HanchorBio, said:

“HCB101 was designed to enable innate immune activation in combination settings by selectively blocking the CD47-SIRPα axis while preserving hematologic tolerability. In HER2-positive gastric cancer, combining dual HER2-directed antibodies with CD47 blockade is a mechanism-based approach to increase tumor opsonization and enhance macrophage-mediated phagocytosis. The consistency of tumor reduction observed across patients and dose levels provides early support for this design strategy.”

Despite advances in first-line HER2-positive gastric cancer treatment, including antibody- and immunotherapy-based combinations, clinical benefit remains constrained by the depth and durability of response. Current regimens have improved response rates, but translating these responses into sustained disease control and survival benefit remains an ongoing challenge. The early activity observed with HCB101 in combination with dual HER2-targeted therapy suggests a potentially differentiated approach, where innate immune activation may further enhance the clinical impact of established antibody backbones. Continued enrollment and follow-up will be important to determine the magnitude and durability of the benefit.

HCB101 is a rationally engineered SIRPα-IgG4 Fc fusion protein developed using HanchorBio’s FBDB™ platform to selectively block the CD47-SIRPα innate immune checkpoint while minimizing hematologic toxicity. By reducing red block cell binding while preserving macrophage-mediated phagocytosis, HCB101 is designed to enable combination use with established antibody- and chemotherapy-based regimens.

In preclinical studies, HCB101 demonstrated robust antitumor activity across multiple gastric cancer animal models, including HER2-positive models and patient-derived xenograft (PDX) models, with tumor growth inhibition (TGI) ranging from 83% to 110%. The current clinical observations provide early translational support for findings.

HanchorBio is currently advancing HCB101 in multiple combination studies across gastric cancer, colorectal cancer, head and neck cancer, and triple-negative breast cancer. Ongoing enrollment and follow-up are expected to further characterize safety, dose optimization, durability of response, and survival outcomes, and to define the potential role of HCB101 within combination paradigms.

About HCB101

HCB101 is a rationally engineered SIRPα–IgG4 Fc fusion protein developed using 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 red blood cell binding, a limitation that historically constrained development across the CD47 class. HCB101 is being evaluated across multiple clinical settings as both monotherapy and combination therapy.

About HanchorBio

Based in Taipei, Shanghai, and the San Francisco Bay Area, HanchorBio (7827.TPEx) is a global clinical-stage biotechnology company focused on immuno-oncology and immune-mediated diseases. The company’s proprietary Fc-based designer biologics (FBDB™) platform enables the design of multi-functional biologics intended to modulate innate and adaptive immune pathways with structural control over safety, exposure, and manufacturability. HanchorBio is advancing a portfolio of differentiated biologics designed to address significant unmet medical needs through innovative molecular engineering and scalable CMC strategies.