Consistently Good Clinical Response in Patients with Early Axial Spondyloarthritis After 3 Years of Continuous Treatment with Etanercept: Longterm Data of the ESTHER Trial

Objective: In patients with early active axial spondyloarthritis (axSpA) with a disease duration of < 5 years, the longterm efficacy of 3 years of continuous etanercept (ETN) treatment was assessed.

Methods: In a previously reported ESTHER trial, patients with axSpA were randomized to treatment with ETN (n = 40) versus sulfasalazine (SSZ; n = 36) in the first year. We analyzed the clinical, laboratory, and magnetic resonance imaging (MRI) response in the pooled dataset of patients (study population; n = 61), including patients with ankylosing spondylitis (AS, n = 31) and nonradiographic axSpA (nr-axSpA, n = 30) who were continuously treated with ETN for 3 consecutive years. Data were analyzed using the last observation carried forward and completer analysis.

Results: In the entire group of patients in the study population (n = 61), the mean Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) decreased from 5.7 (± 1.3) at baseline to 2.6 (± 2.4) at Year 3. The Ankylosing Spondylitis Disease Activity Score (ASDAS) decreased from 3.4 (± 0.8) to 1.5 (± 1.0). Also, mean values for MRI spine and sacroiliac joint scores showed a significant decrease. Response rates in the nr-axSpA group were similar and at least as good compared to the AS group for all outcome measures. When comparing remission stages, we found that ASDAS inactive disease correlated better with C-reactive protein and MRI remission than with Assessment of SpondyloArthritis international Society partial remission.

Conclusion: There was a consistent and sustained clinical response in patients with early axSpA treated with ETN over 3 years. ClinicalTrials.gov registration number NCT00844142.