Harbour BioMed Gains FDA Clearance for First-in-Human Study of B7H4xCD3 Bispecific Antibody HBM7004

Harbour BioMed announced that the FDA has cleared its Investigational New Drug (IND) application for HBM7004, enabling initiation of a Phase I first-in-human study in patients with advanced solid tumors. The trial will evaluate safety, tolerability, pharmacokinetics, and preliminary anti-tumor activity in multiple cancer types.¹

The clearance marks an important regulatory step for the company as it expands its oncology pipeline focused on next-generation bispecific antibody therapies designed to improve tumor-selective immune activation.

B7H4xCD3 Bispecific Designed for Tumor-Directed T Cell Engagement

HBM7004 is a bispecific antibody targeting B7H4 and CD3, developed using Harbour BioMed’s HBICE® platform. The molecule is designed to redirect T cells toward B7H4-expressing tumor cells, enabling localized immune activation within the tumor microenvironment while limiting systemic immune stimulation.¹

B7H4 is an immune checkpoint protein broadly expressed across multiple solid tumors and associated with immune evasion mechanisms.³ CD3-targeting bispecific antibodies are a class of T cell–redirecting therapies that induce MHC-independent tumor cell killing through direct engagement and activation of cytotoxic T cells.²

Preclinical Data Show Anti-Tumor Activity and Combination Potential

According to Harbour BioMed, preclinical studies demonstrated that HBM7004 induced B7H4-dependent T cell activation within tumor environments and showed strong anti-tumor activity across multiple in vivo models. The therapy also exhibited favorable pharmacokinetics and reduced systemic toxicity in preclinical testing.¹

Combination studies further indicated synergistic activity when paired with a B7H4x4-1BB bispecific antibody at low effector-to-target ratios, suggesting potential for dual-costimulatory strategies to enhance T cell activation while maintaining tolerability.¹

These findings are consistent with broader efforts to improve the therapeutic window of T cell–engaging antibodies in solid tumors, where tumor microenvironment barriers and safety constraints remain key challenges.⁴

Expanding Role of Bispecific Antibodies in Solid Tumors

Bispecific antibodies targeting CD3 have become one of the most active areas of oncology drug development, particularly following clinical validation in hematologic malignancies such as multiple myeloma and B-cell cancers. However, translating these approaches to solid tumors remains more complex due to antigen heterogeneity and immunosuppressive tumor microenvironments.⁴

Targets such as B7H4 are of growing interest because of their tumor-selective expression profile and limited distribution in normal tissues, making them attractive candidates for immune redirection strategies. Despite this promise, cytokine release syndrome and on-target off-tumor toxicity remain central concerns for CD3-based therapies in solid tumors.

Harbour BioMed Platform Strategy

HBM7004 was developed using Harbour BioMed’s HBICE® platform, which enables the creation of heavy-chain-only antibody-based immune cell engagers. The platform is designed to support modular development of multispecific antibody formats with tunable immune activation properties.¹

The company continues to expand its oncology pipeline through internal R&D, global collaborations, and antibody engineering platforms aimed at accelerating discovery of next-generation biologics for cancer and immune-mediated diseases.

Clinical Outlook

With IND clearance secured, HBM7004 will enter a Phase I dose-escalation study in patients with advanced solid tumors. The trial will focus on safety and pharmacokinetics while assessing early signs of anti-tumor efficacy.

Bispecific T cell–engaging therapies have demonstrated strong clinical impact in hematologic malignancies, but their role in solid tumors remains under active investigation as developers work to improve safety and tumor penetration.⁴

References

1. Harbour BioMed. (2026, May 8). Harbour BioMed announces U.S. FDA IND clearance for HBM7004 for the treatment of advanced solid tumors. PR Newswire. https://www.prnewswire.com/news-releases/harbour-biomed-announces-us-fda-ind-clearance-for-hbm7004-for-the-treatment-of-advanced-solid-tumors-302766800.html
   
2. June, C. H., & Sadelain, M. (2018 Jul 4). Chimeric antigen receptor therapy. New England Journal of Medicine. https://www.nejm.org/doi/full/10.1056/NEJMra1706169
   
3. Dawidowicz, M., Kot, A., & Mielcarska, S. (2024 Apr 8). Prognostic Value of B7H4 Expression in Patients with Solid Cancers: A Systematic Review and Meta-Analysis Cancers. https://www.mdpi.com/1422-0067/25/9/5045
   
4. Chen, T. T. (2022 Jan 30). Conditionally active T cell engagers for the treatment of solid tumors: rationale and clinical development. Expert Opinion on Biological Therapy. https://www.tandfonline.com/doi/10.1080/14712598.2022.2098674