The US Food and Drug Administration (FDA) has cleared the investigational new drug (IND) application for HCB303 developed by HanchorBio, a global clinical-stage biotechnology company developing next-generation immunotherapies for oncology and immune-mediated diseases.
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 humanised 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 signalling, HCB303 is designed to intercept TIGIT ligands – including PVR/CD155 and CD112. By trapping these ligands, HCB303 is designed to reduce TIGIT-mediated inhibitory signalling while potentially preserving CD226 expression and associated activating signalling 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 tumour microenvironment.
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 tumours who have no remaining standard treatment options.
The study will evaluate safety, tolerability, pharmacokinetics, pharmacodynamics, immunogenicity, biomarkers, and preliminary antitumor activity.
