Objectives Tumour necrosis factor inhibitors (TNFi) are effective in psoriatic arthritis (PsA) and axial spondyloarthritis (axSpA), but are associated with a small (0.6%) increase in serious infection risk, patient burden due to need for self-injection and high costs. Treat-to-target (T2T) tapering might ameliorate these drawbacks, but high-quality evidence on T2T tapering strategies is lacking in PsA and axSpA.

Methods We performed a pragmatic open-label, monocentre, randomised controlled non-inferiority (NI) trial on T2T tapering of TNFi. Patients with PsA and axSpA using a TNFi with ≥6 months stable low disease activity (LDA) were included. Patients were randomised 2:1 to disease activity-guided T2T with or without tapering until withdrawal and followed-up to 12 months. Primary endpoint was the difference in proportion of patients having LDA at 12 months between groups, compared with a prespecified NI margin of 20%, estimated using a Bayesian prior.

Results 122 patients (64 PsA and 58 axSpA) were randomised to a T2T strategy with (N=81) or without tapering (N=41). The proportion of patients in LDA at 12 months was 69% for the tapering and 73% for the no-tapering group: adjusted difference 5% (Bayesian 95% credible interval: −10% to 19%) which confirms NI considering the NI margin of 20%. The mean percentage of daily defined dose was 53% for the tapering and 91% for the no-tapering group at month 12.

Conclusions A T2T TNFi strategy with tapering attempt is non-inferior to a T2T strategy without tapering with regard to the proportion of patients still in LDA at 12 months, and results in a substantial reduction of TNFi use.

Trial registration number NL 6771.