Tumor Necrosis Factor-α Inhibition in Ankylosing Spondylitis and Nonradiographic Axial Spondyloarthritis: Treatment Response, Drug Survival, and Patient Outcome.

Objective: The purpose of this study was to (1) evaluate baseline characteristics of nonradiographic axial spondyloarthritis (nr-axSpA) and ankylosing spondylitis (AS) treated with tumor necrosis factor-α inhibitors (TNFi), (2) assess the response to first TNFi treatment, and (3) compare drug-survival duration and rates.

Methods: Inclusion criteria were patients with axSpA who initiated first TNFi treatment between April 2001 and July 2014 and were followed up for at least 3 months. Efficacy criteria were an improvement of at least 2 points (on a 0-10 scale) or a 50% improvement in the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI).