Discontinuation of biologic DMARDs in non-systemic JIA patients: a scoping review of relapse rates and associated factors.

Background: Biologic disease-modifying antirheumatic drugs (bDMARDs) have changed the treatment of juvenile idiopathic arthritis (JIA) patients notably, as bDMARDs enable substantially more patients to achieve remission. When sustained remission is achieved, tapering or even discontinuation of the bDMARD is advocated, to reduce side effects and costs. However, when and how to discontinue bDMARD therapy and what happens afterwards, is less known.

Objectives: With this scoping review we aim to collect available data in current literature on relapse rate, time to relapse (TTR) and possible flare associated variables (such as time spent in remission and method of discontinuation) after discontinuing bDMARDs in non-systemic JIA patients.

Methods: We performed a literature search until July 2022 using the Pubmed database. All original studies reporting on bDMARD discontinuation in non-systemic JIA patients were eligible. Data on patient- and study characteristics, the applied discontinuation strategy, relapse rates and time to relapse were extracted in a standardized template.

Results: Of the 680 records screened, 28 articles were included in this review with 456 non-systemic JIA patients who tapered and/or stopped bDMARD therapy. Relapse rate after discontinuation of bDMARDs, either abruptly or following tapering, were 40-48%, 36.8-45.0% and 60-78% at 6, 8 and 12 months respectively. Total relapse rate ranged from 26.3% to 100%, with mean time to relapse (TTR) of 2 to 8.4 months, median TTR 3 to 10 months. All studies stated a good response after restart of therapy after flare. JIA subtype, type of bDMARD, concomitant methotrexate use, treatment duration, tapering method, age, sex, and time in remission could not conclusively be related to relapse rate or TTR. However, some studies reported a positive correlation between flare and antinuclear antibodies positivity, younger age at disease onset, male sex, disease duration and delayed remission, which were not confirmed in other studies.

Conclusion: Flares seem to be common after bDMARD discontinuation, but little is known about which factors influence these flares in JIA patients. Follow up after discontinuation with careful registration of patient variables, information about tapering methods and flare rates are required to better guide tapering and/or stopping of bDMARDs in JIA patients in the future.