AB1578-HPR COMPARATIVE ANALYSIS OF THE LONG TERM EFFICACY AND SAFETY OF BIOSIMILAR INFLIXIMAB ADMINISTERED BY CONVENTIONAL DOSAGE REGIMEN VERSUS MODIFIED DOSAGE REGIMEN IN REAL-LIFE CLINICAL SETTINGS: A MULTI-CENTRE STUDY
Authors: P. K. Sarma
Journal: Annals of the Rheumatic Diseases (2024)

<h3>Background:</h3> Ankylosing spondylitis (AS) is a frequently occurring chronic progressive inflammatory disease which results in joint degeneration and diminished physical fitness. Infliximab is a tumour necrosis factor-alpha (TNF alpha) inhibitor, which is considered as a suitable therapeutic approach in patients with AS refractory to conventional disease modifying anti-rheumatic drugs (DMARDs). Several studies have established the effectiveness and safety of Infliximab biosimilars in the real-world clinical settings of Rheumatology. <h3>Objectives:</h3> This multicentre study assessed the long-term efficacy and safety of Infliximab biosimilar (Infimab) administered <i>via</i> a conventional dosage regime [infliximab at 5 mg/kg at week 0, 2, and 6 (induction period) followed by 5 mg/kg every 6–8 weeks (maintenance period)] compared to a modified dosage regime [infliximab at 5 mg/kg at week 0 and 2 (induction period) followed by 3 mg/kg at week 6 and then 8-weekly (maintenance period)] in patients with AS during routine clinical practice. <h3>Methods:</h3> The multicentre study was conducted in real world clinical settings across 10 centres in India and included male and female patients with AS aged ≥18 years. The overall study duration was 1 year and 3 months (April 2022–July 2023). The clinical improvement in patients was assessed by changes in the Ankylosing Spondylitis Disease Activity Score (ASDAS), Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), and C-reactive protein (CRP) level from the baseline to 54 weeks including 4 follow-up visits. <h3>Results:</h3> A total of 100 patients with AS were recruited, of whom 14 patients discontinued the study. Among the total study participants, 47 patients were administered infliximab biosimilar <i>via</i> the conventional dose-regime and the remaining 39 patients were treated with a modified dose-regime as per the discretion of the clinician. Of the treated patients, 63.82% and 38.46% of the patients in the conventional and modified dosage regimens, respectively completed four infusions. At the end of 4 visits, the BASDAI score, ASDAS score, and CRP levels were recorded and the mean values of each was computed. In comparison to visit 1, there was a reduction of 27.01% and 25.98% in the BASDAI score in patients treated with conventional and modified dosage regimens, respectively, by the end of visit 4. There was no significant change in the ASDAS score between the first and fourth visits between both regimes (conventional: 41.8 % and modified: 41.9%). There was a significant change in the average CRP levels in patients receiving infusions. A reduction of 23.95% was observed in patients treated with a conventional dosage-regime while a reduction of 21.7% was seen in patients treated with modified dosage-regime. Overall, only one patient from the study population was not responding after the third dose. No adverse events were reported during the total study period. <h3>Conclusion:</h3> The modified dosage regime was found to be non-inferior to the conventional dosage regime in patients with AS. The approach of dose reduction would have valuable implications in substantially increasing affordability and medical cost savings. A dose reduction would also enable lowering the incidence of serious adverse events. <h3>REFERENCES:</h3> [1] Koo BS, Lim YC, Lee MY, Jeon JY, Yoo HJ, Oh IS, et al. Dose reduction of tumor necrosis factor inhibitor and its effect on medical costs for patients with ankylosing spondylitis. Rheumatology and Therapy. 2021;8:347-59. [2] Gratacós J, Pontes C, Juanola X, Sanz J, Torres F, Avendaño C, et al. Non-inferiority of dose reduction versus standard dosing of TNF-inhibitors in axial spondyloarthritis. Arthritis research &amp; therapy. 2019;21:1-0. <h3>Acknowledgements:</h3> I acknowledge. <h3>Disclosure of Interests:</h3> <b>None declared.</b>