Shanghai, Mar 13th, 2023, Haihe Biopharma Co., Ltd. (hereby referred to as "Haihe Biopharma" or the “Company”) - focused on the discovery, development and commercialization of innovative oncology drugs, announces first patient dosed in Australia in a phase I multi-center clinical trial of BET-BD2 Inhibitor HH3806, Haihe Biopharma’s de novo developed innovative drug with global rights.

This trial is an international, multi-center first-in-human study to evaluate safety, tolerability and pharmacokinetic characters of HH3806 in patients with advanced solid tumors.

HH3806 is a BD2-selective BET (bromodomain and extra-terminal domain) small molecule inhibitor. BETs have been proven to be driving oncogenes in multiple solid cancers and hematological malignancies. Pan-BET inhibitors has no selectivity on BD2 over BD1 domains, leading to undesirable side effects alongside efficacy in clinic. The new generation BET inhibitors selectively target BD2 domains, maintain inhibition on oncogenes and avoid some toxicity of pan-BET inhibitors, with potential of a better therapeutic window. Currently, there is no BET inhibitor approved in any country. Several BET-BD2 inhibitors have entered phase I/II clinical trials. As a highly selective BET-BD2 inhibitor, HH3806 showed potent anti-tumor efficacy, desirable pharmacokinetic characters, acceptable safety and drug-like properties with preclinical studies.

Haihe Biopharma Co., Ltd is a global, values-based, R&D driven biopharmaceutical leader headquartered in China with operation centers in the US and Japan, focusing on the research, development, manufacturing and commercialization of innovative anti-tumor therapies. The Company aims to discover and deliver life-saving therapies to cancer patients world widely. As an R&D focused company led by an academician of the Chinese Academy of Engineering, Haihe Biopharma is committed to in-house innovation. The Company has a full R&D and management team with global perspectives and is proactively mapping out its global drug development strategy. The Company currently has thirteen drug candidates. As of today, Haihe Biopharma has received total 33 clinical trial approvals and has been conducting clinical trials in four major countries.