A phase I, randomized, double-blind, single-dose pharmacokinetic study to evaluate the biosimilarity of SB16 (proposed denosumab biosimilar) with reference denosumab in healthy male subjects

BackgroundSB16 is a biosimilar to reference denosumab (DEN). This study assessed pharmacokinetic (PK) equivalence and evaluated pharmacodynamic (PD), safety, tolerability, and immunogenicity between SB16, European Union-sourced DEN (EU-DEN), and United States-sourced DEN (US-DEN).Research design and methodsIn this double-blind, parallel group, and single-dose study, healthy male subjects were randomized 1:1:1 to receive a single 60 mg dose of either SB16, EU-DEN, or US-DEN subcutaneously. PK, PD, safety, and immunogenicity were evaluated for 197 days. Primary PK endpoints were area under the concentration-time curve (AUC) from time zero to infinity, AUC from time zero to the last quantifiable concentration, and maximum serum concentration (Cmax). Equivalence was determined if 90% confidence intervals (CIs) for the ratio of geometric least squares means (LS Means) were within the equivalence margin of 0.80 to 1.25. ResultsA total of 168 subjects (56 per treatment group) were randomized. All of the corresponding 90% CI of geometric LS Means ratio of primary PK parameters were within the pre-defined equivalence margin. PD, safety, and immunogenicity profiles were also comparable between the treatment groups. ConclusionThis study demonstrated PK bioequivalence between SB16, EU-DEN, and US-DEN in healthy male subjects.TrialRegistrationCT.gov identifier: NCT04621318