Harbour BioMed announced the dosing of the first patient in its part 2 of phase I (phase Ib/IIa) clinical study of its next-generation anti-CTLA-4 antibody, where Australian patients with metastatic or advanced melanoma, hepatocellular carcinoma (HCC) and renal cell carcinoma (RCC) and other type of tumors will be enrolled (study no. 4003.1). The objective of this study is to evaluate the safety, tolerability, PK/PD, and anti-tumor activity of HBM4003 as a single agent in multiple solid tumor types. The part 1 of phase I trial study results have been submitted to European Society of Medical Oncology (ESMO).

As Harbour BioMed's next-generation anti-CTLA-4 antibody, HBM4003 is currently in an open label, multicenter global trial for patients with advanced solid tumors. The part 1 study was focused on dose escalation, and phase Ib/IIa study is to proceed to dose expansion to further explore the anti-tumor activities of HBM4003 in multiple solid tumor types.

"In our previous study, we observed a case of good tumor shrinkage in a man with metastatic liver cancer," said Professor Paul de Souza from St George Private Hospital (Australia). "I look forward to this new stage of the study, which will allow us to recruit more patients with particular cancers that may benefit from this treatment."

"HBM4003 has shown strong anti-tumor activity and great safety in its phase 1 clinical studies," Dr. Jingsong Wang, Founder, Chairman and CEO of Harbour BioMed said. "We will continue to accelerate the global development of HBM4003 for multiple tumor types, so that we can help cancer patients around the world to live better and longer lives."

About HBM4003

HBM4003 is the fully human anti-CTLA-4 monoclonal heavy chain only antibody (HCAb) generated from Harbour Mice?. HBM4003 shows enhanced antibody-dependent cell cytotoxicity (ADCC) killing activity and is extremely specific to high CTLA-4 Treg cells in tumor tissues. The potent anti-tumor efficacy and differentiated pharmacokinetics with durable pharmacodynamic effect presents a favorable product profile. This novel and differentiated mechanism of action has the potential to improve efficacy while significantly reducing the toxicity of the drug.

About Harbour BioMed

Harbour BioMed (HKEX: 02142.HK) is a global biopharmaceutical company committed to the discovery, development and commercialization of novel antibody therapeutics focusing on oncology and immunology. The Company is building its robust portfolio and differentiated pipeline through internal R&D capability, collaborations with co-discovery and co-development partners and select acquisitions.

The Company's proprietary antibody technology platforms Harbour Mice? generate fully human monoclonal antibodies in two heavy and two light chain (H2L2) format, as well as heavy chain only (HCAb) format. Building upon the HCAb antibodies, the HCAb-based immune cell engagers (HBICE?) are capable of delivering tumor killing effects unachievable by traditional combination therapies. Integrating Harbour Mice? with single B cell cloning platform, our antibody discovery engine is highly unique and efficient for development of next generation therapeutic antibodies.