INTRODUCTION

This study aimed to demonstrate the interchangeability of biosimilar CT-P17 and European Union reference adalimumab (EU-adalimumab) in a repeated-switch scenario.

METHODS

In this ongoing, randomized, double-blind, active-controlled, phase 3 study, adults with moderate-to-severe plaque psoriasis received 80 mg EU-adalimumab on day 1, then 40 mg 1 week later and every other week until week 11. At week 13, patients were randomized (1:1, via an interactive web response system) to continue EU-adalimumab ("continuous" group) or undergo repeated switches between CT-P17 and EU-adalimumab ("switching" group). Dosing was via subcutaneous administration. The primary endpoints were area under the concentration-time curve and maximum serum concentration between weeks 25 and 27 (AUC_tau,W25-27 and C_max,W25-27, respectively). Secondary endpoints comprised additional pharmacokinetic (PK) parameters, efficacy, safety, and immunogenicity. Week 27 findings are presented.

RESULTS

The first patient provided signed informed consent on November 7, 2022. Week 27 visits were completed by August 14, 2023. Of 367 patients enrolled, 346 were randomized (switching group, n = 172; continuous group, n = 174). The ratios of least squares means between groups and associated 90% confidence intervals (CIs) for AUC_tau,W25-27 and C_max,W25-27 were 99.45% (94.11-105.08%) and 100.45% (95.03-106.17%), respectively. For both endpoints, 90% CIs fell within the predefined equivalence margin of 80-125% and criteria were greater than calculated t values, satisfying bioequivalence. Additional PK endpoints and efficacy, safety, and immunogenicity findings were similar between groups. Safety profiles were in line with those previously reported.

CONCLUSIONS

Week 27 primary PK results demonstrated bioequivalence, and the overall study results supported the interchangeability of CT-P17 and EU-adalimumab.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT05495568.