Drug Discov Ther. 2025;19(4):253-261. (DOI: 10.5582/ddt.2025.01044)
Switching from originator infliximab to biosimilar infliximab in Japanese patients with rheumatoid arthritis achieving clinical remission (the IFX-SIRIUS study I): An interventional, multicenter, open-label, single-arm clinical trial with clinical, ultrasound and biomarker assessments
Shimizu T, Kawashiri SY, Koga T, Kiya R, Morita M, Kuroda S, Tashiro S, Sato S, Yano H, Asano T, Saito K, Yoshitama T, Ueki Y, Eiraku N, Yamada Y, Okano T, Ushio Y, Dobashi H, Itami T, Tomita D, Nozaki Y, Hosogaya N, Yamamoto H, Kawakami A
Rheumatoid arthritis (RA) is a systemic inflammatory disease characterized by the presence of autoantibodies, with infliximab (IFX), the first biological disease-modifying anti-rheumatic drug (DMARD) targeting tumor necrosis factor α, significantly improving treatment but prompting the development of cost-effective biosimilar DMARDs due to its high cost. This study aimed to investigate the efficacy and safety of switching from originator to biosimilar IFX, CT-P13, in patients with RA using musculoskeletal ultrasound (MSUS) and clinical disease activity indices. This prospective, open-label, interventional, single-arm clinical trial involved a 24-week follow-up, enrolling patients with RA who had achieved clinical remission during treatment with originator IFX. CT-P13 was switched from the originator IFX with an unchanged dosing regimen for 24 weeks. The study utilized not only clinical disease activity indices but also MSUS and serum cytokines/chemokines. Eighteen patients were evaluated during the study period. From baseline to week 24, two of the 18 patients experienced clinical relapse (11.1% [95% CI: 3.1–32.8]). No changes were observed in the MSUS score, including total grayscale and power Doppler scores, Disease Activity Score 28 (DAS28)-erythrocyte sedimentation rate, DAS28-C-reactive protein, Health Assessment Questionnaire-Disability Index, and van der Heijde-modified total Sharp score from baseline to week 24. Serum levels of multiple cytokines/ chemokines showed no apparent changes. Three non-serious adverse events occurred, with no study discontinuations due to adverse events. In conclusion, most RA patients undergoing treatment with originator IFX in clinical remission could safely switch to CT-P13 without an increased risk of relapse, as evidenced by MSUS, clinical indices, and biomarker levels.
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