Experience with adalimumab biosimilar use in clinical practice: Data from the german biker-registry

ABSTRACT

Background: In 2017, Adalimumab Biosimilars became approved. Comparative studies to the originator have been performed in adult patients with rheumatoid arthritis, ankylosing spondylitis and psoriasis and extrapolation led to approval for juvenile idiopathic arthritis (JIA). Objectives: So far there is limited experience with biosimilars in JIA The large national data base of the BIKER-registry was used to describe experience with Adalimumab biosimilars in clinical practice Methods: This retrospective analysis used data of the German BIKER-registry. The data basis war screened for patients exposed to Adalimumab. Subcohorts with initiation of treatment after 2017, use of the originator and of biosimilars were built. 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, 1173 JIA patients were reported to have received Adalimumab. 352 treatments have been started after January 1, 2017. A biosimilar was used first line in 44 patients. Further 55 patients switched for the originator to a biosimilar. 2 patient switched from a biosimilar to the originator. 3 patients switched to a second biosimilar while 5 patients who switched from the originator to a biosimilar reswitched back to the originator. After 2017, 33 pediatric rheumatology centres reported initiation of Adalimumab treatment. 17 have used a biosimilar. 15 centres have swichted at least 1 patient from the originator to a biosimilar and 14 have used first line a biosimilar in at least 1 patient. In a single centre, initiation of a biosimilar was used more frequently (8 versus 7). The patients' characteristics and disease activity parameters were brightly comparable. The JIA category rheumatoid factor (RF) negative polyarthritis was less frequent in the biosimilar first cohort while RF positive polyarthritis and psoriatic arthritis was more frequent. In patients with idiopathic uveitis the originator was used more often. In the switching cohort, more patients had RF negative polyarthritis, persistent oligoarthritis but less had psoriatic arthritis and no had RF positive polyarthritis. No difference in disease activity parameters between patients receiving the originator or biosimilars were noted, neither at baseline, during the course of treatment nor at last observation upon treatment (Figure 1). At the time of switching, 46 (92%) had JADAS minimal disease activity (MDA) and 30 (69%) were in JASDAS remission. At last observation, those numbers were comparable with 42 (86%) with JADAS MDA and 28 (57%) with JADAS remission. In total, 45 adverse events (AE) were reported in 45 patients upon biosimilar treatment. 26 patients had 1, 12 patients had 2 and 6 patients reported 3 and 1 reported 4 events. Adverse event of special interest were Infection associated leukopenia (n=1), COVID 19 infection (n=1), Uveitis flare (n=8), other disease deterioration (arthritis flare) (n=20), injection site reaction n=2. A single serious AE was reported. A 16 year old female adolescent was admitted for unexpected CK elevation. In 10 patients, Adalimumab was discontinued, in 2 it was temporarily paused. Conclusion: This article is the first attempt to present a large sample of data on JIA patients exposed to Adalimumab biosimilars. Since approval of Adalimumab-Biosimilars, limited experience from clinical practice is available. Biosimilars are used in a minority of patients and by a minority of centers although no difference in efficacy or safety was noted from our analysis.