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), area under the concentration-time curve (AUC) from time zero to the last quantifiable concentration (AUC), 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, AUC, 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.