Henlius Gets NMPA IND Approval for Phase 1b/2 Trial of PD-L1 ADC HLX43

SHANGHAI, China I December 4, 2024 I Shanghai Henlius Biotech, Inc. (2696.HK) has announced that its investigational new drug (IND) application for a phase 1b/2 clinical trial of HLX43 for Injection, an antibody-drug conjugate (ADC) developed in collaboration with MediLink Therapeutics, has been approved by the China National Medical Products Administration (NMPA). This trial will evaluate HLX43 as a monotherapy or in combination therapy for patients with advanced/metastatic solid tumours. Notably, in November 2023, the phase 1 clinical trial of HLX43 dosed its first subject, marking it as the inaugural PD-L1-targeting ADC to enter clinical trials in China. Currently, no PD-L1 targeting ADC has received global marketing approval.

PD-1/PD-L1 immune checkpoint inhibitors have transformed cancer treatment across various stages. However, some patients with positive PD-L1 expression either do not respond to or develop resistance to these therapies. PD-L1 is present in a wide range of tumour types, including non-small cell lung cancer (NSCLC), colorectal cancer (CRC), triple-negative breast cancer (TNBC), and squamous cell carcinoma, but shows limited expression in normal tissues. This makes PD-L1 a potential target for ADCs, which could provide new treatment options for cancer patients. Currently, there is a significant unmet need for effective treatments for patients who are resistant to PD-1/PD-L1 immunotherapy or have not benefited from standard care, including immunotherapy. ADCs and their combinations with immunotherapies are promising strategies to enhance clinical outcomes for these patients.

HLX43 is one of the pioneering ADC candidates from Henlius to enter clinical development. It aims to overcome issues of non-responsiveness or resistance to PD-1/L1 immunotherapies, addressing the unmet needs of advanced/metastatic patients. HLX43 leverages the selectivity of targeted monoclonal antibodies and a potent cytotoxic agent to exert anti-tumour effects. This is achieved through specific binding to PD-L1 on tumour cells and releasing cytotoxic payloads upon internalisation by these cells. To date, HLX43 has demonstrated promising anti-tumour activity and a favourable safety profile in nonclinical pharmacology, pharmacokinetic studies, and safety evaluations. These study results were presented as a poster at the 2023 European Society of Medical Oncology (ESMO) Congress.

In an ongoing phase 1 clinical trial aimed at assessing the safety, tolerability, and pharmacokinetics of HLX43 in patients with advanced/metastatic solid tumours, a dose escalation to 4.0 mg/kg administered every three weeks via intravenous infusion has been well tolerated. Patients with solid tumours, including non-small cell lung cancer and cervical cancer, who had previously progressed after standard treatments, responded positively to HLX43. Consequently, Henlius plans to initiate a phase 1b/2 clinical trial to further investigate the efficacy and safety of HLX43 both as a monotherapy and in combination therapy in a wider range of patients who have not benefited from standard treatments.

Henlius remains dedicated to addressing unmet medical needs and will continue to leverage its integrated antibody drug R&D platform to develop innovative therapies. The company's goal is to provide more high-quality and affordable therapeutic options for patients globally.