Disease activity-guided tapering of biologics in patients with inflammatory arthritis: a pragmatic, randomized, open-label, equivalence trial.

OBJECTIVE: To evaluate whether disease activity-guided tapering of biologics compared to continuation as usual care enables a substantial dose reduction while disease activity remains equivalent. METHOD: In this pragmatic, randomized, open-label, equivalence trial, adults with rheumatoid arthritis, psoriatic arthritis, or axial spondyloarthritis in low disease activity on stable-dose biologics for ≥ 12 months were randomized 2:1 into either the tapering group, i.e. disease activity-guided prolongation of the biologic dosing interval until flare or withdrawal, or the control group, i.e. maintaince of baseline biologics with a possible small interval increase at the patients request. The co-primary outcome in the intention-to-treat population was met if superiority in ≥ 50% biologic reduction at 18 months was demonstrated and disease activity was equivalent (equivalence margins ± 0.5). RESULTS: Ninety-five patients were randomized to tapering and 47 to control, of whom 37% (35/95) versus 2% (1/47) achieved ≥ 50% biologic reduction at 18 months. The risk difference was statistically significant [35%, 95% confidence interval (CI) 24%-45%], while disease activity remained equivalent [mean difference 0.05, 95% CI -0.12-0.29]. A statistically significant flare risk was observed [tapering 41% (39/95) vs control 21% (10/47), risk difference 20%, 95% CI 4%-35%]; but, only 1% (1/95) and 6% (3/47) had persistent flare and needed to switch to another biological drug. CONCLUSIONS: Disease activity-guided tapering of biologics in patients with inflammatory arthritis enabled one-third to achieve ≥ 50% biologic reduction, while disease activity between groups remained equivalent. Flares were more frequent in the tapering group but were managed with rescue therapy.