Pharmacokinetics and safety of candidate tocilizumab biosimilar CT-P47 administered by auto-injector or pre-filled syringe: a randomized, open‑label, single-dose phase I study

Background: This study compared the pharmacokinetics (PK), immunogenicity, and safety of candidate tocilizumab biosimilar, CT-P47, administered via auto-injector (CT-P47 AI) or pre-filled syringe (CT-P47 PFS), in healthy Asian adults. Research design and methods: In this phase I, multicenter, open-label study, participants were randomized 1:1 to receive a single 162 mg/0.9 mL dose of CT-P47 via AI or PFS. Primary endpoints were area under the concentration–time curve from time zero to infinity (AUC_0–inf) and maximum serum concentration (C_max). PK equivalence was determined if 90% confidence intervals (CIs) for the ratios of geometric least-squares means (gLSMs) were within the predefined 80–125% equivalence margin. Secondary PK parameters, immunogenicity, and safety outcomes were also assessed. Results: Of 314 participants randomized (155 CT-P47 AI; 159 CT-P47 PFS), 310 received the study drug (153 CT-P47 AI; 157 CT-P47 PFS). Primary and secondary PK results, immunogenicity and safety were similar between groups. Ninety percent CIs for the ratio of gLSMs were within the predefined equivalence margin for AUC_0–inf (85.87–102.94) and C_max (82.98–98.16). Conclusions: PK equivalence between CT-P47 AI and CT-P47 PFS was demonstrated in healthy Asian adults, with comparable immunogenicity and safety between the two devices. Trial registration: ClinicalTrials.gov: NCT05617183.