HanchorBio Inc. has reported encouraging Phase 1 results for HCB101, its novel SIRP⍺-engineered Fc fusion protein targeting the CD47-SIRP⍺ axis, demonstrating a favorable safety profile and early signs of antitumor activity in patients with advanced cancers. The data were presented at the 13th International Conference of the Federation of Asian Clinical Oncology (FACO 2025) in Shanghai.
Strong Safety Profile with Minimal Toxicities
The multinational, first-in-human trial (NCT05892718) enrolled 49 patients across 10 dose levels ranging from 0.08 to 18.00 mg/kg administered weekly. Notably, only one dose-limiting toxicity (DLT) was observed throughout the study—a transient Grade 3 thrombocytopenia at the 2.56 mg/kg dose level, as of the July 10, 2025 data cutoff.
Dr. Fangling Ning, an investigator at the Affiliated Hospital of Binzhou Medical University, highlighted the therapy's differentiated profile: "HCB101 is showing early promise as a differentiated therapy targeting the CD47-SIRP⍺ axis, with encouraging signals of efficacy in both solid tumors and lymphomas. Importantly, the novel design (engineered with the help of AI) effectively mitigated anemia and cytopenias, which have been challenges with prior agents in this class."
Robust Receptor Engagement and Early Efficacy Signals
The study demonstrated consistent receptor occupancy with >90% CD47 receptor occupancy achieved at doses ≥1.28 mg/kg. This high level of target engagement translated into encouraging antitumor activity, with two confirmed partial responses observed in head and neck squamous cell carcinoma (HNSCC) and non-Hodgkin lymphoma patients, alongside durable disease control in multiple patients.
Differentiated Approach to CD47 Targeting
HCB101 represents a 3.5th-generation, affinity-optimized SIRP⍺-Fc fusion protein with an intact IgG4 Fc backbone, developed using HanchorBio's proprietary FBDB™ platform. The therapy is engineered for selective CD47 targeting with low red blood cell binding, thereby avoiding the anemia and thrombocytopenia commonly associated with earlier anti-CD47 monoclonal antibodies.
Key differentiators include enhanced safety with a cytopenia-sparing profile, no DLTs observed up to 24 mg/kg, and >90% receptor occupancy at ≥1.28 mg/kg, supporting a broad therapeutic window. The therapy is also engineered to enhance antibody-dependent cellular phagocytosis (ADCP) and bridge innate-to-adaptive immunity.
Broad Clinical Activity Across Multiple Tumor Types
Preclinical studies demonstrated HCB101's activity across >80 PDX and CDX models, with early clinical signals observed in gastric cancer, triple-negative breast cancer, head and neck squamous cell carcinoma, non-Hodgkin lymphoma, and ovarian cancer. The therapy shows durable disease control as monotherapy and achieved a 100% confirmed partial response rate (6/6) in second-line gastric cancer when combined with ramucirumab and paclitaxel.
Pipeline Expansion with Next-Generation Immunotherapy
HanchorBio also announced the development of HCB301, a tri-specific checkpoint immunotherapy designed to integrate three synergistic mechanisms: CD47-SIRP⍺ blockade to activate macrophage-mediated phagocytosis, PD-1 inhibition to restore exhausted T cells, and TGF-β pathway suppression to improve the tumor microenvironment. Preclinical studies demonstrated enhanced immune activation and potent antitumor activities, with first results to be presented at SITC 2025.
Comprehensive Conference Presentation Strategy
The company plans to showcase its pipeline momentum across five major international oncology congresses in Q4 2025, including presentations at FACO, SITC, ESMO Asia Congress, ASH Annual Meeting, and ESMO Immuno-Oncology Congress. These presentations will highlight both HCB101 monotherapy data from the HCB101-101 study and combination data from the HCB101-201 study (NCT06771622).
Scott Liu, Ph.D., Chairman, CEO, and Founder of HanchorBio, emphasized the significance of these developments: "We are encouraged by the excellent safety profile and initial responses observed in heavily pretreated patients. These monotherapy data establish safety, PK/PD, and early activity, providing the foundation for our ongoing combination trials testing HCB101 layered onto standard backbones in multiple tumor types."
