Switching tumor necrosis factor inhibitors in the treatment of axial spondyloarthritis

Objective To assess the impact of switching tumor necrosis factor (TNF)-alpha inhibitors on patients with axial spondyloarthritis (axSpA). Methods PubMed literature searches were conducted using combinations of search terms including ankylosing spondylitis, spondyloarthropathy, spondyloarthritis, switch/switching, drug survival, and TNF/tumor necrosis factor to identify published articles with data on outcomes related to switching biologic therapies in patients with axSpA. Results Of the 134 studies screened, 21 were identified as reporting data on switching TNF inhibitors in patients carrying a diagnosis of axSpA or ankylosing spondylitis. The most common reasons for switching from the first TNF inhibitor were lack of efficacy (14–68%), loss of efficacy (13–61%), and adverse events/poor tolerability (13–57%). Switching TNF inhibitors was beneficial for a substantial proportion of patients with axSpA who failed to respond to initial or even second TNF inhibitor therapy and adverse effects were not enhanced. Drug survival rates were generally lower for the second (47–72% at 2 years) or third TNF inhibitor (49% at 2 years) than for the first TNF inhibitor (58–75% at 2 years). Predictors of responses in TNF-naïve patients included HLA-B27 positivity, absence of enthesitis, age ≤40 years, elevated C-reactive protein level, good functional status, and shorter disease duration. Predictors of drug survival included male sex and peripheral arthritis. Common characteristics of patients who switched TNF inhibitors included female sex, older age, more severe disease, greater symptom burden, higher erythrocyte sedimentation rate, complete ankyloses, and enthesitis. Conclusion When the first or even the second TNF inhibitor fails, switching to an alternate one is not an unreasonable clinical therapeutic decision.