Safety and Efficacy of Switching from Originator to CT-P13 Infliximab Biosimilar in Patients Affected By Spondyloarthritis. a 6-Month Observational Study

Background/Purpose: 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. (1,2) Switching from originator 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.(3) Aim of the study was to investigate efficacy and safety of switching from originator to biosimilar INX in patients affected by spondyloarthritis (SpA) in real life clinical practice. Methods: Thirty-six patients (18 with diagnosis of AS, 7 with enteropathic arthritis, 8 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 originator 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. A six months evaluation of BASDAI, BASFI, ASDAS-CRP, DAS28-CRP ( if peripheral disease), MASES, VAS pain and collection of adverse events (AE) were performed. Results: At switch, patients had a median age of 51.8 years (range 23-80 yrs), with a median disease duration of 137,1 months (range 14-372) and median ongoing treatment with originator INX of 76.4 months (range 14-372). After 6 months of biosimilar INX therapy we cannot find any statistical difference in terms of median values of BASDAI (2.66 ± 1.6 Vs 2.5 ± 1.4 p= 0.31), BASFI (2.3 ± 1.3 Vs 2.2 ± 1.2 p= 0.051), ASDAS-CRP (1.39 ± 0.4 Vs 1.38 ± 0.4 p= 0.8), DAS28-CRP (2.66 ± 0.69 Vs 2.67 ± 0.34 p= 0.93), MASES (0.33 ± 0.66 Vs 0.2 ± 0.4 p= 0.08), VAS pain (18.1 ± 14.7 Vs 16.7 ± 11.3 p= 0.55). 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=0.13). Two patients (5.5%) stopped biosimilar INX therapy, after the first two administrations, for the appearance of de novo psoriasis. Conclusion: No statistically significant 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 originator 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. Yoo D-H, Hrycaj P, Miranda P, et al. “A randomised, double-blind, parallel-group study to demonstrate equivalence in efficacy and safety of CT-P13 compared with innovator infliximab when co-administered with methotrexate in patients with active rheumatoid arthritis: the PLANETRA study”. Ann Rheum Dis 2013;72:161320 Yoo D.H., Prodanovic N.,Jaworski J. et Al. “Efficacy and safety of CT-P13 (biosimilar infliximab) in patients with rheumatoid arthritis: comparison between switching from reference infliximab to CT-P13 and continuing CT-P13 in the PLANETRA extension study”. Ann Rheum Dis 2015-208786