Introduction: Tumor necrosis factor (TNF) antagonists reduce the signs and symptoms of spondyloarthritides, including ankylosing spondylitis (AS) and psoriatic arthritis (PsA). Our objective was to evaluate the effectiveness and safety of adalimumab, 40 mg every other week, for patients with AS or PsA and prior treatment with infliximab (IFX) and/or etanercept (ETN).
Methods: Both trials were 12-week, open-label studies with an optional extension period up to week 20. Patients were stratified by history of anti-TNF treatment, prior anti-TNF therapy received (IFX, ETN, or both), and reason for discontinuation of prior TNF antagonist. ETN was discontinued>or=3 weeks, and IFX was discontinued>or=2 months before the first adalimumab administration. Effectiveness at week 12 was evaluated by using observed standard-outcome measurements for AS and PsA.
Results: At week 12 of adalimumab treatment, Bath Ankylosing Spondylitis Disease Activity Index 50 responses were achieved by 40.8% of 326 patients with AS who had received prior anti-TNF therapy and by 63.0% of 924 patients with AS who were naive to TNF antagonist. Observed response rates were generally greater for patients who discontinued the prior anti-TNF therapy because of loss of response or intolerance than for patients who discontinued because of lack of response. Median changes in swollen-joint count and in enthesitis score were similar in patients with and without prior TNF-antagonist treatment. Modified PsA response criteria were fulfilled by 71.2% of 66 patients with PsA, with prior exposure to TNF antagonists, and by 78.8% of 376 patients with no history of anti-TNF therapy. The percentages of patients with PsA attaining a Physician's Global Assessment of psoriasis of "Clear/Almost clear" increased from 33.3% to 61.0% for patients with prior IFX and/or ETN treatment and from 34.6% to 69.7% for patients without anti-TNF therapy. The median change in the Nail Psoriasis Severity Index was -6 for both groups. In both studies, patterns of adverse events were similar for patients with and without prior anti-TNF therapy and were consistent with the known safety profile of adalimumab.
Conclusions: Patients with AS or PsA previously treated with IFX and/or ETN experienced clinically relevant improvements of their diseases after 12 weeks of adalimumab.