Henlius' HLX43 doses first patient in Australia, accelerating global development of potential best-in-class PD-L1 ADC

On September 18, 2025, Henlius announced that the first patient dosing in the international multicenter Phase II clinical trial (HLX43-NSCLC201) of HLX43 for Injection—its innovative programmed death-ligand 1 (PD-L1) antibody-drug conjugate (ADC)—in patients with advanced non-small cell lung cancer (NSCLC) was completed in Australia.

HLX43 is a potential best-in-class (BIC) broad-spectrum anti-tumor ADC, featuring a dual mechanism of action: immune checkpoint blockade and payload cytotoxicity.

Preclinical studies have demonstrated that HLX43 exhibits therapeutic potential in multiple tumor types—including NSCLC, cervical cancer, and esophageal squamous cell carcinoma—even in cases resistant to PD-1/PD-L1 monoclonal antibodies, with favorable tolerability.

Its Phase I clinical data were first presented at the 2025 American Society of Clinical Oncology (ASCO) Annual Meeting. The results showed that HLX43 demonstrated significant "high efficacy and low toxicity" in solid tumors such as NSCLC and tonsillar squamous cell carcinoma (TSCC). Moreover, it exhibited efficacy in NSCLC patient populations regardless of squamous or non-squamous histology, presence or absence of EGFR mutations, presence or absence of brain/liver metastases, and PD-L1 positive or negative status, without reliance on biomarker screening.

Henlius is fully advancing the global clinical development of this innovative molecule. International multicenter Phase II studies have been successively initiated in China, the United States, Japan, Australia, and other regions. Prior to this, the company had already completed the first patient enrollment for this study in China and the United States.

To date, no ADC products targeting PD-L1 in the same class have been approved for marketing globally.