OP0163 COMPARATIVE ANALYSIS OF ETANERCEPT BIOSIMILAR AND ORIGINATOR USE IN CLINICAL PRACTICE: DATA FROM THE GERMAN BIKER-REGISTRY
Authors: G. Horneff, D. Windschall, T. Hospach, S. Mrusek, M. Rühlmann, A. Klein
Journal: Annals of the Rheumatic Diseases (2021)

Background: In 2017, 2 Etanercept biosimilars became approved. Comparative studies performed in adult patients with rheumatoid arthritis, ankylosing spondylitis or psoriasis by extrapolation led to approval for juvenile idiopathic arthritis (JIA). Objectives: So far there is limited experience with Etanercept biosimilars in JIA: The large national data base of the BIKER-registry was used to describe experience with Etanercept biosimilars in clinical practice. Methods: In this retrospective analysis patients exposed to ETA were identified in the German BIKER-registry and grouped into cohorts according to initiation of treatment after 2017, use of the originator and of biosimilars. The course of JADAS10, Physician global assessment VAS 0–100-mm, Parent/patient global assessment VAS 0–100-cm, Active joint count 0-71, truncated at 10, ESR and CHAQ-DI was analyzed. Descriptive statistics was used for demographic, clinical data, drug exposure, adverse events (AEs) and events of special interest (ESI). Results: Until 31.10.2020, 2917 JIA patients were reported to have received Etanercept. Since January 1 2017, in 39 centres treatment with Etanercept was started in 439 patients (377 (85.9%) started with the originator and 62 (14.1%) started a Biosimilar). Biosimilars were prescribed n 17 centres (44%). In 12 centres (31%), Etanercept biosimilars were used first line in 62 patients. In 17 centres (44%), 63 patients switched for the originator to a biosimilar. 3 patients reswitched from the biosimilar to the originator. 4 patient switched from a biosimilar to the originator). 22 centres (56%) had not prescribed a biosimilars so far. In not a single centre, initiation of a biosimilar was more frequent than of the originator. The patients’ characteristics and disease activity parameters were widely comparanble. Patients receiving biosimilar first line were slightly older at disease onset and had a longer disease duration. Patients receiving biosimilar first line had more often rheumatoid factor (RF) negative polyarthritis while extended oligoarthritis was more frequent in the originator cohort. In the switching cohort, more patients had extended oligoarthritis and fewer had RF negative polyarthritis and ERA JIA. No difference in disease activity parameters was noted, neither at baseline, during the course of treatment nor at last observation upon treatment. A decrease of the JADAS10 indicates improvement in both groups (Figure 1). At the time of switching, 68% had JADAS minimal disease activity (MDA) and 43% were in JASDAS remission. At month 6 and 12 these numbers increased to 74%/65% and 62%/50%. In total, 66 adverse events (AE) were reported in 45 patients upon biosimilar treatment. 33 patients had 1, 5 patients 2, 5 patients had 3 and 2 reported 4 events. Adverse event of special interest were hypersensitivity n=1, injection site reaction n=1, new onset of psoriasis n=1, celiac disease n=1, Crohn‘s diesease n=1, elevated transaminases n=2, depression n=1 and disease deterioration (arthritis flare) in n=21. In 20 patients, the etanercept biosimilar was discontinued. Conclusion: This analysis is the first attempt to present a large data sample on JIA patients exposed to Etanercept biosimilars. Biosimilar were used in a minority of patients and by a minority of centers although no difference in efficacy or safety was noted from our analysis. Until today, the use of the originator is by far exceeding the use of biosimilars. The prescription of a biosimilar either first line or by switching from the originator is limited to a part of centres. Differences in efficacy between first line biosimilar users and originator users could not be observed. Also, after switching, no loss of efficacy was observed. Disclosure of Interests: Gerd Horneff Speakers bureau: Pfizer, Daniel Windschall: None declared, Toni Hospach: None declared, Sonja Mrusek: None declared, Michael Rühlmann: None declared, Ariane Klein: None declared