BASELINE INFLAMMATORY MARKERS AND DISEASE ACTIVITY INDICES PREDICT TAPERING OF BIOLOGIC AGENTS IN ANKYLOSING SPONDYLITIS

Abstract

Rationale. Clinicians need to have evidence-based information regarding the feasibility of tapering biologics in ankylosing spondylitis (AS). Objective. The study aims to identify significant predictors of tapering in clinical practice. Methods and results. AS patients on their first tumor necrosis factor alpha inhibitor (iTNFα) were enrolled between 2015-2017 and followed until the end of the observation or until tapering or switch of their iTNFα. Binary logistic regression was used to predict tapering (“0” for “non-tapering”, meaning switches and original posology; “1” for “tapering”), significant if p < 0.05. Of the 120 included patients, 50.8% had adalimumab, 21.7% etanercept, 4.2% golimumab and 23.3% infliximab. During follow-up, 40.8% tapered their initial iTNFα, 40.8% remained on its original posology, 16.7% switched it and 1.7% were lost. Judging by odds ratios (OR), inflammatory markers (e.g. odds ratio ORCRP = 0.936, p = 0.014) and activity scores (ORBASDAI = 0.565, p = 0.005) significantly reduced the chance for tapering. Compared to patients on the original posology, patients on tapering had a significantly lower prevalence of uveitis ever (6.8% compared to 11.0%, p = 0.008, post-hoc χ2 test). Discussion. In a real life setting, no more than half of AS patients treated with TNFα inhibitors can undergo tapering. High baseline inflammatory markers and disease activity indices significantly lower the chance of tapering. From a therapeutic point of view, a non-responsive disease phenotype of AS can be hypothesized and it includes extra-spinal manifestations such as uveitis.

Keywords

• ankylosing spondylitis
• tnf inhibitors
• tapering