Pharmacokinetics and safety of candidate tocilizumab biosimilar CT-P47 versus reference tocilizumab: a randomized, double-blind, single-dose phase I study

Background: CT-P47 is a candidate tocilizumab biosimilar. This study assessed the pharmacokinetic (PK) equivalence of CT-P47 and European Union-approved reference tocilizumab (EU-tocilizumab) in healthy Asian adults. Research design and methods: This double-blind, multicenter, parallel-group trial randomized healthy adults (1:1) to receive a single (162 mg/0.9 mL) subcutaneous dose of CT-P47 or EU-tocilizumab. The primary endpoint (Part 2) was PK equivalence by area under the concentration–time curve (AUC) from time zero to last quantifiable concentration (AUC_0–last), AUC from time zero to infinity (AUC_0–inf), and maximum serum concentration (C_max). PK equivalence was concluded if 90% confidence intervals (CIs) for the ratios of geometric least-squares means (gLSMs) were within the 80–125% equivalence margin. Additional PK endpoints, immunogenicity, and safety were evaluated. Results: In Part 2, 289 participants were randomized (146 CT-P47; 143 EU-tocilizumab); 284 received study drug. AUC_0–last, AUC_0–inf, and C_max were equivalent between CT-P47 and EU-tocilizumab: 90% CIs for the ratios of gLSMs were within the 80–125% equivalence margin. Secondary PK endpoints, immunogenicity, and safety were comparable between groups. Conclusions: CT-P47 demonstrated PK equivalence with EU-tocilizumab and was well tolerated, following a single dose in healthy adults. Clinical trial registration: www.clinicaltrials.gov identifier is NCT05188378.