Safety and pharmacokinetics of a new biosimilar trastuzumab (HL02): a Phase I bioequivalence study in healthy Chinese men

Objectives: The study aimed to explore the bioequivalence of a proposed biosimilar HL02 vs. its reference products (US-trastuzumab) among healthy Chinese men. Methods: In this study, nine healthy male subjects received single ascending doses of trastuzumab biosimilar (HL02, 2-8 mg/kg), and then a randomized, double-blind, two-arm, parallel study was conducted to investigate the PK similarity of HL02 (6 mg/kg) with that of US-trastuzumab as a reference drug. Results: PK properties exhibited by HL02 (N = 55) were similar to those of US-trastuzumab (N = 52). The comparison of biosimilarity with US-trastuzumab showed that the 90% confidence intervals (CIs) of the ratios for C-max, AUC(0-t), and AUC(0-infinity) were within 80-125%. Nineteen subjects were positive for ADA and negative for NAb in both HL02 and US-trastuzumab groups. In total, 81.67% of subjects in HL02 and 78.95% in US-trastuzumab groups showed treatment-related mild or moderate adverse events, mild elevation of transaminase level being the most common adverse events (AE) recorded. Conclusions: The PK characteristics and immunogenicity exhibited by HL02 were similar to that of the reference product, US-trastuzumab. The safety profiles were similar in both the treatment groups with mild-moderate adverse effects.