HENLIUS (02696) has announced that the first patient in China (excluding Hong Kong, Macau, and Taiwan) has been dosed in a Phase 2/3 clinical study. The trial is evaluating HLX22, a recombinant humanized anti-HER2 monoclonal antibody injection, in combination with HLX87, a HER2-targeting antibody-drug conjugate, as a first-line treatment for patients with HER2-positive recurrent or metastatic breast cancer (BC).

This study is an open-label, randomized, multicenter Phase 2/3 clinical trial designed to assess the efficacy of HLX22 combined with HLX87 as a first-line therapy for HER2-positive recurrent or metastatic breast cancer. The trial consists of two stages. The first stage is an open-label, multicenter, randomized, parallel-controlled Phase 2 study. Eligible participants will be randomly assigned in a 2:2:1:1 ratio to receive one of the following treatments: HLX22 plus HLX87, pertuzumab plus HLX87, pertuzumab plus trastuzumab deruxtecan, or pertuzumab plus trastuzumab and docetaxel. The primary endpoints for the first stage are objective response rate (ORR) and progression-free survival (PFS), as assessed by an independent imaging review committee.

The second stage is an open-label, multicenter, randomized, parallel-controlled Phase 3 study. In this stage, eligible participants will be randomly assigned in a 1:1 ratio to receive either HLX22 combined with HLX87 or pertuzumab combined with trastuzumab and docetaxel. The primary endpoint for the second stage is PFS, also evaluated by an independent imaging review committee.

The main objective of the study is to evaluate the clinical efficacy of HLX22 in combination with HLX87 as a first-line treatment for HER2-positive recurrent or metastatic breast cancer. Secondary objectives include assessing the safety, tolerability, pharmacokinetics, and immunogenicity of the combination therapy, as well as exploring potential predictive or resistance biomarkers.