ABSTRACT Background HLX02, the first China-manufactured trastuzumab biosimilar, is approved in Europe (EU) and China. This study evaluated bioequivalence between HLX02 and US-approved trastuzumab (US-trastuzumab). Method In this double-blind, parallel-group, Phase I study, healthy Chinese men were randomized (1:1:1) to receive a single 6 mg/kg dose of HLX02, reference US-trastuzumab, or reference EU-approved trastuzumab (EU-trastuzumab). Equivalence in PK profiles was demonstrated if the 90% confidence intervals (CIs) for the geometric mean ratio (GMR) for the difference between the least square means of the area under the curve (AUC) from time 0 to infinity (AUC∞) were 0.8–1.25. Results Pharmacokinetic profiles of the three trastuzumab products were similar in 111 Chinese men. Equivalence was confirmed between HLX02 and US-trastuzumab (GMR for AUC∞ 1.009, 90% CI 0.950–1.072); HLX02 and EU-trastuzumab (GMR for AUC∞ 1.068, 90% CI 1.005–1.135); and EU- and US-trastuzumab (GMR for AUC∞ 0.945, 90% CI 0.889–1004). Exploratory analysis of all other PK parameters also demonstrated equivalence between any two of the three trastuzumab products. HLX02 had similar safety and immunogenicity profiles to US- and EU-trastuzumab. Conclusion HLX02 is bioequivalent to US-trastuzumab and EU-trastuzumab, with similar safety and immunogenicity profiles. US- and EU-trastuzumab were also bioequivalent to each other.
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