Background: Etanercept is a human recombinant protein that functions as a competitive inhibitor of tumour necrosis factor-alpha (TNF-alpha), a pro-inflammatory molecule exerting a key role in the pathogenesis of psoriatic arthritis (PsA).
Methods: Seventy-one patients affected by PsA with variable skin involvement, refractory to conventional anti-rheumatic drugs, were treated with 50 mg etanercept subcutaneous injections twice-weekly for 12 weeks, followed by a maintenance dose regimen of 25 mg twice-weekly for an additional 12 weeks. Efficacy and safety were assessed at 12-24 weeks. Efficacy criteria was the global assessment of a patient's joint symptoms expressed by the Ritchie index (RI), while skin symptoms were assessed by the psoriasis area and severity index (PASI). The impact of etanercept on patients' quality of life (QoL) was measured by four validated QoL instruments.
Results: At week 12, all patients showed a reduction of symptoms with improvement of mean RI (mRI) of 66.1% from baseline and a reduction of mean PASI (mPASI) from 8.8 to 3.2. At week 24, there was a mRI reduction of 78.4% as well as a mPASI reduction to 1.7. Psoriasis-specific QoL measures improved throughout therapy.
Conclusions: A high-dose regimen of etanercept is a highly effective and tolerable treatment for PsA with variable skin involvement, although a larger study population group and a longer trial would be needed to draw strong conclusions about the safety of the higher dose.