HCB303 features a differentiated TIGIT-Fc strategy designed to intercept TIGIT ligands, preserving the CD226 activating axis while simultaneously targeting PD-L1 and CD47

Plans to initiate a Phase 1 first-in-human, dose-escalation, multi-regional trial in patients with advanced solid tumors

TAIPEI and SHANGHAI and SAN FRANCISCO, Oct. 5, 2026 /PRNewswire/ — HanchorBio, Inc. (TWSE: 7827), a global clinical-stage biotechnology company developing next-generation immunotherapies for oncology and immune-mediated diseases, today announced that the U.S. Food and Drug Administration (FDA) has cleared the investigational new drug (IND) application for HCB303. The clearance enables HanchorBio to initiate its Phase 1 first-in-human clinical trial.

HCB303 is HanchorBio’s second trispecific immunotherapy to enter clinical development and represents an innovative and differentiated approach to enhance immune response against cancer. A humanized trispecific fusion protein engineered via HanchorBio’s proprietary FBDB™ platform, HCB303 incorporates a TIGIT-Fc ligand-trap strategy within a single architecture that simultaneously targets the TIGIT/PVR, PD-L1/PD-1, and SIRPα/CD47 pathways.

Unlike conventional anti-TIGIT antibodies that primarily bind to TIGIT and block TIGIT receptor signaling, HCB303 is designed to intercept TIGIT ligands—including PVR/CD155 and CD112. By trapping these ligands, HCB303 is designed to reduce TIGIT-mediated inhibitory signaling while potentially preserving CD226 expression and associated activating signaling in T cells and NK cells. Combined with PD-L1 blockade and SIRPα-mediated enhancement of macrophage phagocytosis, HCB303 aims to coordinate complementary innate and adaptive antitumor immunity within the tumor microenvironment.

“We believe TIGIT-Fc offers a biologically superior strategy to conventional anti-TIGIT receptor blockade,” said Scott Liu, PhD, Founder and Chairman of HanchorBio. “Simply blocking PVR signaling through an anti-TIGIT antibody may release the inhibitory signal, but it does not address the down-regulation of CD226, which is needed for enhanced activation of T and NK cells. HCB303 was designed to go further—intercepting immune-inhibiting TIGIT ligands and preserving the CD226 activating axis, while simultaneously blocking the PD-L1 and CD47 pathways. This is precisely the type of biology-driven therapeutic architecture our FBDB™ platform was built to create.”

The FDA clearance follows pre-IND feedback from the agency in August 2026. HanchorBio will now proceed with its planned Phase 1 first-in-human, dose-escalation, multi-regional study (HCB303-ONC-101) in patients with advanced, relapsed, or refractory solid tumors who have no remaining standard treatment options. The study will evaluate safety, tolerability, pharmacokinetics, pharmacodynamics, immunogenicity, biomarkers, and preliminary antitumor activity.

“HCB303 is HanchorBio’s second trispecific immunotherapy to enter clinical development, and the FDA clearance moves HCB303 from a differentiated biological hypothesis into clinical testing,” added Alvin Luk, PhD, MBA, President and CMO (Group) & CEO (USA) of HanchorBio. “Our priority now is to rigorously evaluate whether its differentiated TIGIT biology and coordinated engagement of innate and adaptive immunity translate into meaningful clinical benefit for patients. With HCB301 already in clinical development and HCB303 now cleared to enter the clinic, we are advancing the potential of our FBDB™ platform to generate mechanistically distinct multispecific therapeutics.”

About HCB303

HCB303 is an investigational, humanized trispecific fusion protein developed using HanchorBio’s proprietary FBDB™ platform. It is designed to simultaneously modulate the SIRPα/CD47, PD-L1/PD-1, and TIGIT/PVR immune pathways, integrating macrophage, T-cell, and NK-cell antitumor immunity within a single engineered molecule.

About HanchorBio

HanchorBio (TWSE: 7827) is a global clinical-stage biotechnology company focused on inventing and developing next-generation biologics for cancer and immune-mediated diseases using its proprietary FBDB™ platform.

HanchorBio’s pipeline includes HCB101, its lead SIRPα-based innate immune checkpoint program; HCB301, a clinical-stage trispecific immunotherapy targeting SIRPα, PD-L1, and TGF-β biology; HCB303, a clinical-stage trispecific immunotherapy integrating SIRPα/CD47, PD-L1/PD-1, and TIGIT/PVR biology; and additional programs across oncology and immune-mediated diseases. For more information, please visit: https://www.HanchorBio.com.

Forward-Looking Statements

This press release contains forward-looking statements, including statements regarding the development and clinical advancement of HCB303; the timing, initiation, design, conduct, and potential outcomes of future clinical studies; the potential therapeutic characteristics, mechanisms, safety, and antitumor activity of HCB303; the development of HanchorBio’s pipeline; and the capabilities and potential of the FBDB™ platform. These statements are based on current expectations and assumptions and involve risks and uncertainties that could cause actual results to differ materially from those described. FDA clearance of an IND permits clinical investigation to proceed but does not constitute approval of HCB303 or provide assurance regarding the safety, efficacy, timing, or success of its clinical development. HanchorBio undertakes no obligation to update forward-looking statements except as required by applicable law.

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SOURCE HanchorBio Inc.