Shanghai Henlius Biotech (2696) recently announced that the first patient has been dosed in a Phase 1b/2 clinical study evaluating HLX43 (an anti-PD-L1 antibody-drug conjugate) in combination with HLX07 (a recombinant anti-EGFR humanised monoclonal antibody) or Hansizhuang (serplulimab injection) for the treatment of advanced or metastatic colorectal cancer in Chinese Mainland.

According to the announcement, the study will proceed in two parts. Part 1 comprises dose-escalation and dose-expansion phases to assess safety, tolerability, and preliminary efficacy of HLX43 at different dose levels combined with a fixed dose of HLX07. Part 2 will evaluate HLX43, at distinct dose levels, with a fixed dose of Hansizhuang in patients with metastatic colorectal cancer. Secondary objectives include appraising pharmacokinetic and immunogenicity profiles, as well as exploring potential predictive or resistance biomarkers.

HLX43 is an antibody-drug conjugate targeting PD-L1, designed for advanced or metastatic solid tumors. Previous trials in non-small cell lung cancer, cervical cancer, and esophageal squamous cell carcinoma have indicated favorable safety and promising preliminary efficacy. HLX07 is intended for advanced solid tumors, with Phase 2 clinical trials underway in various indications. Hansizhuang, already approved for several lung and esophageal cancer indications in Chinese Mainland and other markets, is being further developed in multiple global clinical studies.

No similar combination therapy featuring these investigational agents has been approved for marketing worldwide. The announcement states there is no guarantee of successful development and commercialization, and advises caution when dealing in the company’s shares.