Delayed treatment with a tumor necrosis factor alpha blocker associated with worse outcomes in patients with spondyloarthritis: data from the Czech National Registry ATTRA

Introduction: The administration of biologic disease-modifying antirheumatic drugs, including tumor necrosis factor (TNF)-α inhibitors, is observed to interfere with the disease activity and progression. In this study, we aimed to assess the effectiveness and response predictors of adalimumab (ADA), a TNF-α blocker, in patients with axial spondyloarthritis (AxSpA).

Methods: This study was a historical prospective, registry-based observational study on patients with AxSpA treated with first-line ADA after conventional drug failure. For evaluation and comparison, patients were divided into three groups according to the number of years from AxSpA diagnosis to initiation of ADA treatment: (A) <5 years, (B) 5-10 years, and (C) >10 years. The assessment instruments ankylosing spondylitis disease activity score (ASDAS), Bath ankylosing spondylitis activity index (BASDAI), Bath ankylosing spondylitis functional index (BASFI), health assessment questionnaire (HAQ), Short Form 36 questionnaire (SF-36), and EuroQoL 5 dimension questionnaire (EQ-5D) were regularly administered for up to 24 months of follow-up.

Results: This study included 1043 patients with AxSpA (9.2% with non-radiographic AxSpA, 68.9% men). By month 6, a significantly higher proportion of patients with ASDAS remission (<1.3) was achieved upon earlier intervention in group A (30.1%) and B (32.9%) than in the late intervention group C (22.6%) (p ⩽ 0.05). At month 6, lower age and better BASFI at treatment initiation were identified as the strongest predictors of ASDAS remission in both univariable [odds ratio (OR): 0.956, p ⩽ 0.001; OR: 0.834, p ⩽ 0.001, respectively] and multivariable analyses (OR: 0.963, p ⩽ 0.001; OR: 0.859, p ⩽ 0.001, respectively). Earlier intervention also led to improvement in most patient-reported outcomes (PROs) based on HAQ, SF-36, and EQ-5D.

Conclusion: Results from the ATTRA registry concur with previous clinical trials that supported efficacy of TNF-α blockers and showed better treatment outcomes with early interventions, including reduction of disease activity and improvement in PROs. We identified age and BASFI as the main factors influencing treatment effectiveness.