OBJECTIVES: Many patients with rheumatoid arthritis (RA) require treatment with tumour necrosis factor inhibitor (TNFi) to reach remission. It is debated whether tapering of TNFi to discontinuation should be considered in sustained remission. The aim of ARCTIC REWIND TNFi was to assess the effect of tapering TNFi to withdrawal compared with stable treatment on the risk of disease activity flares in patients with RA in remission ≥1 year. METHODS: This randomised, open-label, non-inferiority trial was undertaken at nine Norwegian rheumatology departments. Patients with RA in remission ≥12 months on stable TNFi therapy were allocated by computer-based block-randomisation to tapering to discontinuation of TNFi or stable TNFi. Conventional synthetic disease-modifying antirheumatic co-medication was unchanged. The primary endpoint was disease flare during the 12-month study period (non-inferiority margin 20%), assessed in the per-protocol population. RESULTS: Between June 2013 and January 2019, 99 patients were enrolled and 92 received the allocated treatment strategy. Eighty-four patients were included in the per-protocol population. In the tapering TNFi group, 27/43 (63%) experienced a flare during 12 months, compared with 2/41 (5%) in the stable TNFi group; risk difference (95% CI) 58% (42% to 74%). The tapering strategy was not non-inferior to continued stable treatment. The number of total/serious adverse events was 49/3 in the tapering group, 57/2 in the stable group. CONCLUSION: In patients with RA in remission for more than 1 year while using TNFi, an increase in flare rate was reported in those who tapered TNFi to discontinuation. However, most regained remission after reinstatement of full-dose treatment. TRIAL REGISTRATION NUMBERS: EudraCT: 2012-005275-14 and clinicaltrials.gov: NCT01881308.