Background Anti-TNF therapy is successful for achieving low disease activity or clinical remission in patients with axial spondyloarhritis (axSpA). Nevertheless, this therapy has not clearly shown to slow or inhibit radiographic progression in these patients. Based on this, it is unclear what therapeutic attitude should be adopted once remission has been achieved in patients with axSpA.
Objectives To evaluate if anti-TNF tapering is efficacious for maintaining remission or low disease activity (LDA) in patients with spondyloarthritis (axSpA).
Methods A systematic literature review until August 2014 was performed using Medline, EMBASE and Cochrane databases. The research question was formulated according to the PICOS method: Population (axSpA patients); Intervention (anti-TNF dose tapering); Outcome (flare or change on disease activity); and Setting (longitudinal studies with at least 6 months of follow up after dose adjustment). Data was extracted using a form developed for this specific purpose. Results are shown as median (range) and relative frequencies in percentages.
Results In total, 8 studies from 763 citations were included. All studies included patients with ankylosing spondylitis from single centers and no study included patients with non-radiographic axSpA. The study design was retrospective cohort (n=3), prospective cohort (n=3), non-randomized trial (n=1) and RCT (n=1). In these studies, patients receiving standard doses of anti-TNF therapy who were in remission (BASDAI<2 and normal CRP) or with LDA (BASDAI<4 and normal CRP) reduced anti-TNF therapy dose according to an established protocol (n=6) or to the physician's criterion (n=2). The characteristics of the studies were as follows: total number of patients 43 (8-136), number of patients on low-dose regimen 21 (8-109) and follow-up period after anti-TNF tapering 12 (6-21) months. Administered anti-TNF therapy was etanercept (n=5), infliximab (n=1) and adalimumab/etancercept/infliximab (n=2). Baseline characteristics of patients included in the studies were as follows: age 41 (35-54) years old, 78% (75-90) males, disease duration 9 (3-13) years, 89% (75-91) HLA-B27+. Time in remission or LDA before reducing anti-TNF dose was provided in four studies and it was heterogeneous: <3 months (n=1) and at least 3 (n=1) or 6 (n=2) months. The percentage of patients maintaining LDA or remission after reducing anti-TNF dose was reported in 5 out of the 7 studies. These were 47%, 75%, 53-81%, 86% and 100%. The remaining three studies reported mean change in disease activity measures after reducing anti-TNF therapy. Mean BASDAI in these studies before reducing anti-TNF dose was 2.3, 1.6 and 3.1 and at the end of the study was 0.6, 1.4 and 2.1, respectively. Mean CRP (mg/L) before reducing anti-TNF dose was 0.6, 1.0 and 2.3 and at the end of the study was 0.6, 1.3 and 2.1, respectively. Anti-TNF tapering was most frequently done increasing the interval between drug administration than decreasing the dose of the injection/infusion.
Conclusions Published data indicates that anti-TNF therapy tapering is successful in maintaining remission or LDA during at least one year in a high number (>50%) of patients with AS. Further data are required to identify which patients with axSpA are included within this group.
Disclosure of Interest None declared