Shanghai Henlius Biotech, Inc. announced that, recently, the first patient has been dosed in a phase 1 clinical trial of HLX26 (a recombinant anti-LAG-3 humanized monoclonal antibody injection) (" HLX26 ") independently developed by the Company in combination with HANSIZHUANG (serplulimab injection) ("HANSIZHUANG") for the treatment of advanced/metastatic solid tumours in mainland China (excluding Hong Kong, Macau and Taiwan regions, the same as below). This open-label, dose-escalation, phase 1 clinical study aims to evaluate the safety,
tolerability, pharmacokinetic characteristics, and preliminary efficacy of HLX26 in combination with HANSIZHUANG in patients with advanced/metastatic solid tumours. Eligible patients were given different doses of HLX26 and fixed-dose HANSIZHUANG intravenously every three weeks following 3+3 dose-escalation design. The primary endpoints of this study are the dose-limiting toxicity (DLT) and maximum tolerated dose (MTD) determined within three weeks after the initial dose. Secondary endpoints include adverse events, pharmacokinetic parameters, immunogenicity, and preliminary efficacy. HLX26 is an innovative humanized monoclonal antibody targeting Lymphocyte-activation gene 3 ("LAG-3") extracellular domains independently developed by the Company, which is projected to be used for the treatment of solid tumours and lymphomas. In October 2021, the first subject has been dosed in the phase 1 clinical trial of HLX26 for the treatment of solid tumours and lymphomas in mainland China. HLX26 blocks the interaction between LAG-3 and its ligand to block the LAG-3-mediated signaling pathway of inhibiting T-cell function and recover the release of cytokines such as IL-2 and IFN- from T cells, and shows tumour inhibiting effect through blocking immune escape in the tumour microenvironment in combination with HANSIZHUANG. Pre-clinical pharmacodynamics studies both in vivo and in vitro have proved that the combination of HLX26 and HANSIZHUANG has a synergistic effect on restoring the killing function of T cells, showing more significant anti-tumour activity. In April 2022, the application for phase 1 clinical trial of HLX26 in combination
with HANSIZHUANG for the treatment of advanced/metastatic solid tumours or lymphomas was approved by the National Medical Products Administration (the "NMPA"). HANSIZHUANG is an innovative anti-PD-1 monoclonal antibody independently developed by the Company, which is projected to be used for the treatment of a variety of solid tumours. In March 2022, the NMPA approved HANSIZHUANG for the treatment of unresectable or metastatic Microsatellite Instability-High ("MSI-H") solid tumours that have failed to respond to the standard therapy. In September 2021, the new drug application (NDA) for the first-line treatment with HANSIZHUANG in combination with chemotherapy in patients with locally advanced or metastatic squamous non-small cell lung cancer (sqNSCLC) was accepted by the NMPA; in April 2022, the new drug application (NDA) for the first-line treatment with HANSIZHUANG in combination with chemotherapy in previously untreated patients with new indication of extensive stage small cell lung cancer (ES-SCLC) was accepted by the NMPA. In May 2022, the phase 3 clinical study comparing HANSIZHUANG or placebo in combination with chemotherapy as a first-line treatment for patients with locally advanced/metastatic esophageal squamous cell carcinoma (ESCC), met the co-primary endpoints of progression-free survival (PFS) and overall survival (OS) in a planned interim analysis after the assessment of the Independent Data Monitoring Committee (IDMC). In addition to the indication for the MSI-H solid tumours which has been approved for marketing, HANSIZHUANG is being undergone clinical trials in 11 combination therapies with it as the
core in various countries and regions around the world.