A Phase I Study Comparing the Pharmacokinetics, Safety, and Immunogenicity of Proposed Biosimilar GB242 and Reference Infliximab in Healthy Subjects

Objective The objective of this study was to compare the pharmacokinetics (PKs), safety, and immunogenicity of GB242 as a potential biosimilar infliximab with those of reference infliximab in healthy Chinese subjects. Methods We conducted a randomized, single-center, double-blind, parallel-controlled phase I study in which 48 healthy subjects were divided equally into a GB242 group and reference infliximab group. Both the test and reference drug were administered as a single intravenous dose of 3 mg/kg. Blood samples were collected as per a designated schedule to evaluate PKs and immunogenicity. Safety was assessed throughout the study. PK similarity was concluded if the 90% confidence intervals (CIs) for the geometric mean ratios of the GB242 to reference infliximab for maximum concentration ( C max ), area under the concentration–time curve (AUC) from time zero to the last quantifiable concentration (AUC t ), and AUC from time zero to infinity (AUC ∞ ) were within the predefined bioequivalence range of 80–125%. Results The mean serum concentration–time curves were similar between GB242 and reference infliximab. The 90% CIs for the geometric mean ratios of the GB242 to reference infliximab for C max , AUC t , and AUC ∞ were completely within 80–125% for the PK similarity comparison. The proportion of subjects with treatment-emergent adverse events was similar between the GB242 group and the reference infliximab group. Antidrug antibody profiles were comparable between the two treatments groups. Conclusions This study demonstrated high PK similarity between GB242 and its marketed reference infliximab in healthy subjects. Both treatments showed comparable safety and immunogenicity. Registration number ChiCTR-IPR-15007098