SAT0381 Safety and Efficacy of Switching from Innovator To Biosimilar Infliximab in Patients Affected by Spondyloarthritis. A 6-Month Observational Study

Background Biosimilar infliximab (INX) was recently approved by the European Medicine Agency based on comparable pharmacokinetics, safety and efficacy profile to innovator INX for the treatment of Rheumatoid Arthritis, Ankylosing Spondylitis (AS), Crohn's disease, Ulcerative Colitis, Psoriatic Arthritis (PsA), and psoriasis. (1) Switching from innovator to biosimilar INX offers cost savings but, up to now, limited evidence (from conference abstracts of open-label extension studies suggesting similar clinical efficacy) and no guidelines are available. (2) Objectives To investigate efficacy and safety of switching from innovator to biosimilar INX in patients affected by spondyloarthritis (SpA) in real life clinical practice. Methods Thirty-one patients (17 with diagnosis of AS, 4 with enteropathic arthritis, 7 with PsA and 3 with undifferentiated SpA), from three Italian Rheumatologic centers with a previous diagnosis of SpA, treated for more than 6 months with innovator infliximab (in according with the ASAS/EULAR guidelines) and clinically with an inactive or moderate disease activity (ASDAS-CRP <2.1), were switched to biosimilar infliximab for pharmacoeconomic reasons. All patients signed a consent form. A six months evaluation of BASDAI, BASFI, ASDAS-CRP, DAS28-CRP (if peripheral disease), MASES, VAS pain, morning stiffness and collection of adverse events (AE) were performed. Results At switch, patients had a median age of 50,9 years (range 23–80), with a median disease duration of 124,5 months (range 14–372) and median ongoing treatment with innovator INX of 73,7 months (range 6–144). After 6 months of biosimilar INX therapy we cannot find any statistical difference in terms of median values of BASDAI (2.73 ± 1.5 Vs 2.6 ± 1.3 p=0.27), BASFI (2.34 ± 1.3 Vs 2.17 ± 1.2 p=0.051), ASDAS-CRP (1.35 ± 0.3 Vs 1.28 ± 0.2 p=0.24), DAS28-CRP (2.66 ± 0.67 Vs 2.67 ± 0.35 p=0.92), MASES (0.35 ± 0.7 Vs 0.17 ± 0.4 p=0.08), VAS pain (18 ± 14.7 Vs 16,7 ± 11.3 p=0.55). The median duration of morning stiffness was statistically lower 6 months after the switch (7.2 ± 6.9 Vs 5.8 ± 6 p=0.02). During the first six months of biosimilar INX a very low number of patients experienced an AE without a significance difference with the AE collected the six months before the switch (Fisher Test p=1.0). One patient (3%) stopped biosimilar INX therapy, after the first two administrations, for the appearance of a severe palmoplantar psoriasis. Conclusions No statistically significance differences in terms of BASDAI, BASFI, ASDAS-CRP, DAS28-CRP, MASES, VAS pain values and number of adverse events were found six months after the switch from innovator to biosimilar INX in an SpA multicentre Italian cohort. References Park W, Hrycaj P, Jeka S, et al. A randomised, double-blind, multicenter, parallel-group, prospective study comparing the pharmacokinetics, safety and efficacy of CT-P13 and innovator infliximab in patients with ankylosing spondylitis: the PLANETAS study. Ann Rheum Dis 2013;72:160512. Won Park, Pedro Miranda, Marek Brzosko et Al. Efficacy and Safety of CT-P13 (Infliximab Biosimilar) over Two Years in Patients with Ankylosing Spondylitis: Comparison Between Continuing with CT-P13 and Switching from Infliximab to CT-P13. ACR 2015 Abstract Disclosure of Interest None declared