Background

This study’s objective was to demonstrate pharmacokinetic (PK) similarity and safety of denosumab biosimilar, CT‑P41, and United States–licensed reference denosumab (US-denosumab) in healthy male Asian adults, considering also pharmacodynamic (PD) outcomes.

Research design and methods

This double-blind, two-arm, parallel-group, Phase 1 study randomized (1:1) healthy males to a single (60-mg) subcutaneous dose of CT‑P41 or US-denosumab. Primary endpoints were area under the concentration – time curve (AUC) from time zero to infinity (AUC0–inf), AUC from time zero to the last quantifiable concentration (AUC0–last), and maximum serum concentration (Cmax). PK equivalence was determined if 90% confidence intervals (CIs) for ratios of geometric least-squares means (gLSMs) were within the predefined 80–125% equivalence margin. Secondary PK, PD, safety, and immunogenicity outcomes were also evaluated.

Results

Of 154 participants randomized (76 CT‑P41; 78 US-denosumab), 151 received study drug (74 CT‑P41; 77 US-denosumab). Primary and secondary PK results, PD results, safety, and immunogenicity were comparable between groups. Ninety percent CIs for ratios of gLSMs were within the predefined equivalence margin for AUC0–inf (100.4–114.7), AUC0–last (99.9–114.3), and Cmax (95.2–107.3).

Conclusions

Following a single dose in healthy males, CT‑P41 demonstrated PK equivalence with US-denosumab.

PMID: 38349618