Safety and pharmacokinetics of a biosimilar of denosumab (KN012): Phase 1 and bioequivalence study in healthy Chinese subjects.

BACKGROUND: KN012 is a proposed biosimilar candidate for the reference drug denosumab, with the brand name Prolia®. This study explored the tolerance, variability, and pharmacokinetics (PK) of denosumab and its biosimilar in healthy Chinese subjects. RESEARCH DESIGN AND METHODS: A randomized, double-blind, parallel, two-arm study was performed to analyze the bioequivalence of denosumab biosimilar (60 mg) compared with denosumab. RESULTS: The PK properties of denosumab biosimilar were similar to those of denosumab. When denosumab biosimilar was compared to denosumab, the geometric mean ratios (GMRs) of Cmax, AUC0-t, and AUC0-∞ were 98.74%, 102.54%, and 102.18%, respectively, and the 90% confidence interval was observed to be within 80-125%. The inter-subject variability ranged from 31.4% to 34.6%. Five subjects in the denosumab biosimilar group and one subject in the denosumab group were positive for anti-drug antibodies (ADAs) and negative for neutralizing antibodies (NAbs). Adverse reactions were observed in 100% (52 subjects) and 94.0% (47 subjects) of the subjects in the denosumab biosimilar and denosumab groups, respectively. Reductions in the blood calcium and phosphate levels were the most common adverse reactions. CONCLUSION: The PK characteristics were comparable for the denosumab biosimilar and denosumab groups. Their safety profiles were also similar. TRIAL REGISTRATION: : The trial is registered at the Chinese Clinical Trial website (http://www.chinadrugtrials.org.cn/index.html #CTR20181231).