HENLIUS (02696): The Phase 1b/2 clinical study of HLX43 in combination with Hansey (Siltuximab Injection) for the treatment of patients with advanced/metastatic solid tumors has completed the first patient dosing in China.

HENLIUS (02696) announced that, recently, the Phase 1b/2 clinical study of injection HLX43 (targeting PD-L1 antibody - novel DNA topoisomerase I inhibitor conjugate) combined with Hansun (sulquitumab injection) for the treatment of patients with advanced/metastatic solid tumors has completed the first patient dosing in China (excluding the Hong Kong, Macau, and Taiwan regions). This study is aimed at evaluating the safety, tolerability, and efficacy of HLX43 combined with Hansun for the treatment of patients with advanced/metastatic solid tumors in a Phase 1b/2 clinical study. The study is divided into two stages: Phase 1b dose escalation and Phase 2 dose expansion. The first stage is an open-label study where eligible subjects will receive different doses of HLX43 combined with a fixed dose of Hansun intravenous infusion every 3 weeks (Q3W). The second stage is a multicenter, randomized, open-label controlled study that evaluates the safety and efficacy of three different doses of HLX43 combined with a fixed dose of Hansun in patients with advanced non-small cell lung cancer (NSCLC) based on the data from the first stage. The primary endpoint of the first stage is the proportion of subjects in each dose group who experience dose-limiting toxicities (DLTs) during the DLT observation period and the maximum tolerated dose (MTD) of HLX43 combined with Hansun. The primary endpoint of the second stage is the objective response rate (ORR) assessed by the independent imaging review committee (IRRC) based on the Response Evaluation Criteria in Solid Tumors (RECIST) v1.1 in patients with advanced NSCLC. HLX43 is an antibody-drug conjugate (ADC) developed by the company by conjugating a novel DNA topoisomerase I inhibitor small molecule toxin-peptide linker imported from Suzhou Yilian Biopharmaceutical Co., Ltd. in November 2022 with the company's independently developed PD-L1 targeting antibody, intended for the treatment of advanced/metastatic solid tumors. In October 2023, the Phase 1 clinical trial application of HLX43 for the treatment of advanced/metastatic solid tumors was approved by the National Medical Products Administration (NMPA), and the study completed the first patient dosing in China in November 2023. In November 2023, the Phase 1 clinical trial application of HLX43 for the treatment of advanced/metastatic solid tumors was approved by the Food and Drug Administration (FDA). In December 2024, the Phase 1b/2 clinical trial application of HLX43 monotherapy or combination therapy for the treatment of advanced/metastatic solid tumors was approved by NMPA, and the company initiated a Phase 2 clinical trial of HLX43 in potential solid tumor indications including esophageal squamous cell carcinoma (ESCC) in January 2025. In January 2025, the Phase 1b/2 clinical trial application of HLX43 combined with Hansun for the treatment of patients with advanced/metastatic solid tumors was approved by NMPA. Hansun is an innovative anti-PD-1 monoclonal antibody developed by the company. Its approved indications in China include first-line treatment of squamous non-small cell lung cancer (NSCLC) in combination with chemotherapy, extensive-stage small cell lung cancer (ES-SCLC), esophageal squamous cell carcinoma (ESCC), and non-squamous NSCLC. Hansun has also been approved for marketing in the European Union, Indonesia, Cambodia, and Thailand. Hansun for the treatment of small cell lung cancer (SCLC) was granted Orphan Drug Designation by the FDA and the European Commission in April 2022 and December 2022, respectively. Additionally, the company is actively progressing multiple clinical trials of Hansun and related combination therapies globally, covering indications such as lung cancer, esophageal cancer, head and neck squamous cell carcinoma, colorectal cancer, and gastric cancer. Preclinical and clinical data suggest that the combination therapy of antibody-drug conjugates (ADCs) and PD-1/L1 monoclonal antibodies can produce synergistic effects, offering patients a more effective and safe clinical solution. As of the date of this announcement, there are no similar approved combination therapy treatment options available globally.