Comparative pharmacokinetics of an adalimumab biosimilar SB5 administered via autoinjector or prefilled syringe in healthy subjects

Purpose: The objective of this study was to demonstrate comparable pharmacokinetic (PK), safety, and tolerability parameters of the adalimumab biosimilar SB5 administered via autoinjector (AI) pen or prefilled syringe (PFS). Patients and methods: In this phase 1, randomized, open-label, single-dose, parallel-group study, healthy subjects aged 18-55 years were randomized 1:1 to a single dose of 40 mg 5135 delivered subcutaneously via Al or PFS. PK parameters, safety, and tolerability were assessed for 57 days post-dose. The primary endpoint was area under the curve (AUC) of the concentration-time curve from zero to infinity (AUC(inf)) and from zero to last quantifiable concentration (AUC(last)) and maximum serum concentration (C-max). Equivalence was determined using predefined margins of 0.80-1.25 for the 90% CI for the ratio of SB5 AI to SB5 PFS. Results: Ninety-five subjects were randomized to each group. Mean serum concentration-time profiles were superimposable between groups. Mean values for AUC(inf), AUC(last) and C-max were similar between the SB5 Al and SB5 PFS groups. For the primary endpoints, the 90% CIs for the ratio of geometric least squares means for SB5 Al to SB5 PFS ranged between 0.9503 and 1.2240, which were all within the equivalence margin of 0.80-1.25. Incidence of treatment-emergent adverse events and injection site reactions was similar between groups. Conclusion: In healthy subjects receiving a single dose of SB5 via Al or PFS, PK parameters and corresponding 90% CIs were within the predefined margins, showing bioequivalence between the two delivery methods. Safety and tolerability assessments were also similar between groups.