Biosimilars in Saudi Arabia: a single-centre, open-label case series examining infliximab switching

Abstract

Background: A biosimilar version of infliximab ( CT-P13) was recently approved for use in Saudi Arabia. Clinical data support its use in the treatment of rheumatic disease, however, there is a lack of local data regarding the efficacy and tolerability of CT-P13 among patients with rheumatological disorders in Saudi Arabia. Objectives: To investigate the feasibility, tolerability and immunogenicity of switching from originator infliximab to biosimilar infliximab, CT-P13, in patients with rheumatoid arthritis (RA), ankylosing spondylitis (AS) and Behçet’s disease (BD). Methodology: The study included patients who were being treated with originator infliximab in the Department of Rheumatology in Khamis Mushayt General Hospital, Saudi Arabia, and were required to switch to biosimilar infliximab (CT-P13) between January 2018 and June 2019. Patient follow-up was carried out every three months for one year. The disease activity score 28 (DAS28) was used to assess RA severity. The Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) score was used to measure disease activity in patients with AS, while BD disease activity was based on clinical assessment. Results: In total, 13 patients (six with RA, five with AS and two with BD) were switched to biosimilar infliximab. The majority (n = 11/13) remained on biosimilar infliximab throughout the follow-up period with no reported major adverse events. Overall, there was a significant improvement in RA disease activity following biosimilar treatment, with the mean DAS28 decreasing from 3.61±1.24 before biosimilar therapy to 2.63±1.54 one year after switching. Conclusion: In patients with AS, BD, or RA who switched from originator infliximab to the biosimilar, CT-P13, we did not observe any significant differences in tolerability or efficacy between biosimilar and originator. Furthermore, disease activity significantly declined in RA patients following biosimilar treatment