Shanghai, China, June 5, 2026 — Shanghai Henlius Biotech, Inc. (2696.HK) announced that the first patient in the United States has been dosed in the international multicentre Phase 1 clinical trial (HLX17-MRST001) of HLX17, the company’s independently developed pembrolizumab biosimilar (recombinant anti-PD-1 humanised monoclonal antibody injection), intended for the adjuvant treatment of multiple resected solid tumours. Prior to this, the study had already completed first patient dosing in China. Leveraging a global multicentre development strategy, HLX17 is expected to accelerate the accumulation of clinical data across broader patient populations and lay the foundation for future global registration and development.
HLX17 is a pembrolizumab biosimilar independently developed by Henlius in accordance with the NMPA, EMA, FDA and other international biosimilar guidelines. The pharmacologic comparative study, and preclinical pharmacology study, pharmacodynamics, pharmacokinetics and immunogenicity studies have demonstrated that HLX17 is similar to the reference pembrolizumab. Pembrolizumab has been approved in various countries and regions for a range of different indications, such as for the adjuvant treatment of non-small cell lung cancer (NSCLC), melanoma, and renal cell carcinoma (RCC).
This study is a multicentre, randomised, double‑blind, parallel‑controlled Phase I clinical study designed to evaluate the pharmacokinetic (PK) profile, efficacy, safety and immunogenicity of HLX17 vs. US-sourced KEYTRUDA® in patients with multiple resected solid tumours, including non‑small cell lung cancer, melanoma, or renal cell carcinoma. Eligible participants will be randomised in a 1:1 ratio to Arm A or Arm B. Participants in Arm A will receive HLX17 (200 mg) by intravenous infusion once every three weeks (Q3W) starting from Cycle 1, and treatment will continue until 12 months after randomization (approximately 17 cycles) or until the occurrence of disease recurrence, death, initiation of new anti‑tumour therapy, unacceptable drug toxicity, withdrawal of informed consent, or study termination. Participants in Arm B will receive US‑sourced KEYTRUDA® (200 mg) Q3W for the first 8 cycles (24 weeks), after which they will switch to HLX17 200 mg Q3W, and continue treatment until 12 months after randomization or until the discontinuation criteria are met. The primary objective of this study is to evaluate the PK similarity between HLX17 and US‑sourced KEYTRUDA® following single and multiple intravenous infusions, with primary endpoints including the area under the serum concentration–time curve from time 0 to 21 days (AUC0-21d) after the 1st dose, and the area under the serum concentration–time curve within a dosing interval at steady state (AUCss) after the 6th dose. Secondary endpoints include additional PK parameters, efficacy, safety, and immunogenicity.
Looking forward, Henlius will maintain its focus on unmet medical needs and further broaden the company’s layout in more disease areas, commit to bring high quality and affordable treatments for patients worldwide.