Occurrence and prediction of flare after tapering of TNF inhibitors in patients with axial spondyloarthritis.

Abstract

Patients with axial spondyloarthritis (axSpA) in clinical remission tapered Tumor Necrosis Factor inhibitor (TNFi) therapy according to a clinical guideline. During 2-years' follow-up, we aimed to investigate flare frequency, dose at which flare occurred, type of flare and predictors thereof. Patients in clinical remission (Bath ankylosing spondylitis disease activity index (BASDAI)<40, physician global score<40 and without disease activity the previous year) tapered TNFi to 2/3 standard dose at baseline, 1/2 at week (w) 16, 1/3 at w32 and discontinuationed at w48. Flare was defined as: BASDAI flare (BASDAI≥40 and Δ≥20) and/or clinical flare (development of inflammatory back pain, musculoskeletal or extra-articular manifestations and/or ASDAS-CRP increase ≥0.9) and/or MRI flare (≥2 new/worsened inflammatory lesions). Of 108 patients, 106 (99%) flared before 2 years: 29 patients (27%) at 2/3 standard dose, 21 (20%) at 1/2 dose, 29 (27%) at 1/3 dose and 27 (25%) after discontinuation. One-hundred-and-five (99%) had clinical flare, 25 (24%) BASDAI flare and 23 (29% of patients with MRI) MRI flare. Forty-one patients (41%) fulfilled the ASAS-definition of clinically important worsening (≥0.9 increase since baseline). Higher baseline physician global score was an independent predictor of flare after tapering to 2/3 (Odds ratio=1.19 (95% Confidence Interval=1.05-1.41);p=0.011). Changes in clinical and/or imaging variables in the 16 weeks prior to tapering did not predict flare. Almost all (99%) axSpA patients in clinical remission flared during tapering to discontinuation, but above half not before receiving 1/3 dose or less. Higher physician global score was an independent predictor of flare.