To evaluate the clinical response after switching from one tumour necrosis factor (TNF)alpha antagonist to another in patients with ankylosing spondylitis (AS) and psoriatic arthritis (PsA).
In this ongoing, longitudinal, observational study, data were prospectively collected on efficacy and safety since 2000 for patients starting biological treatments. The present analysis was restricted to patients with a diagnosis of spondyloarthropathy (SpA) who switched from one TNFalpha antagonist to another because of inadequate efficacy or adverse events.
In total, 589 anti-TNFalpha-naive patients were registered, of whom 165 had a diagnosis of SpA; 7 patients with AS and 15 with PsA received >1 TNFalpha antagonist. Two patients with PsA were treated with all the drugs. In all, 16 subjects switched from infliximab to etanercept, 7 from etanercept to adalimumab and 1 from etanercept to infliximab. Overall, a clinical response was seen in 75% of patients who changed from infliximab to etanercept, and in 57.1% who switched from etanercept to adalimumab.
The findings of this study on a selected population of patients with SpA indicate that the failure of an initial TNFalpha antagonist does not preclude the response to another one. Further trials are needed to confirm this preliminary observation.