Early Tumor Necrosis Factor α Antagonist Therapy in Everyday Practice for Inflammatory Back Pain Suggesting Axial Spondyloarthritis: Results From a Prospective Multicenter French Cohort

Abstract

To determine the frequency of and factors associated with early tumor necrosis factor α (TNFα) antagonist therapy in everyday clinical practice in patients with suspected axial spondyloarthropathy (SpA). We used data from the prospective observational study in the French Devenir des Spondylarthropathies Indifférenciées Récentes (DESIR; Outcome of Recent Undifferentiated Spondylarthropathies) cohort of 708 patients with recent-onset (<3 years) inflammatory back pain (IBP) suggesting axial SpA. TNFα antagonist use was recorded at months 6 and 12 and factors independently associated with TNFα antagonist therapy were identified by multivariate logistic regression. Among the 708 patients (mean age 33.8 years, 46.2% men), 166 (23.4%) patients received TNFα antagonist therapy by month 12, including 120 (73.6%) patients who fulfilled Assessment of SpondyloArthritis international Society (ASAS) axial criteria and 157 (94.6%) who fulfilled at least 1 SpA criteria set; 109 (65.6%) had no sacroiliitis. Factors independently associated with early TNFα antagonist therapy were high Ankylosing Spondylitis Disease Activity Score using the C-reactive protein level (odds ratio [OR]1-point increase 1.60, 95% confidence interval [95% CI] 1.25-2.03, P < 0.001), high physician's global disease activity score (OR 1.37, 95% CI 1.21-1.54, P < 0.001), ASAS nonsteroidal antiinflammatory drug score >50 (OR 1.88, 95% CI 1.24-2.87, P = 0.003), current or past disease-modifying antirheumatic drug use (OR 2.09, 95% CI 1.22-3.59, P = 0.008), systemic corticosteroid use (OR 2.48, 95% CI 1.43-4.34, P = 0.002), and mild to severe radiographic hip abnormalities (OR 9.43, 95% CI 2.11-42.09, P = 0.003). After adjustment on these factors, Achilles enthesis hypervascularization by power Doppler and number of work days missed were associated with TNFα antagonist therapy. In the DESIR cohort, approximately one-fourth of patients with recent IBP suggestive of axial SpA were under anti-TNFα therapy after 1 year of followup. All factors associated with this early initiation reflected higher disease activity, refractoriness, or severity, which suggests compliance of French rheumatologists with current treatment guidelines.