Shanghai Henlius Biotech, Inc. (Henlius) announced the first patient dosing in an international, multi-center Phase 1 clinical study of HLX17, a biosimilar to pembrolizumab, in patients with multiple resected solid tumours. The trial began in the United States and is running concurrently in mainland China.
The randomized, double-blind study compares the pharmacokinetics, efficacy, safety and immunogenicity of HLX17 with US-sourced KEYTRUDA. Participants are assigned 1:1 to receive either HLX17 (200 mg) every three weeks for up to 12 months or eight cycles of KEYTRUDA followed by HLX17 at the same dose and interval. Primary endpoints focus on pharmacokinetic similarity—specifically AUC0-21d after the first dose and AUCss after the sixth dose—while secondary measures include additional PK parameters, clinical efficacy, safety and immunogenicity.
HLX17, independently developed by Henlius, targets programmed cell death protein 1 (PD-1) and is intended to mirror the approved indications of pembrolizumab, which address a range of cancers such as melanoma, non-small cell lung cancer and gastric cancer. Clinical trial applications for HLX17 were cleared by China’s National Medical Products Administration in September 2024 and by the US Food and Drug Administration in September 2025.
According to IQVIA MIDAS, global sales of pembrolizumab reached USD 35.42 billion in 2025, underscoring the commercial potential of a successful biosimilar entrant.
Henlius cautions that the development and commercialisation of HLX17 remain subject to clinical outcomes and regulatory review.
Comments