Etanercept in the treatment of psoriatic arthritis and psoriasis: a randomised trial

Background Etanercept, a tumour-necrosis-factor inhibitor, has shown effica cy in the treatment of rheumatoid arthritis. Psoriatic arthritis and psoria sis are disease states in which tumour necrosis factor, a proinflammatory c ytokine, is present in increased concentrations in joints and in the shin. Therefore, psoriatic arthritis and psoriasis may be appropriate therapeutic targets for etanercept. Methods This randomised, double-blind, placebo-controlled, 12 week study as sessed the efficacy and safely of etanercept (25 mg twice-weekly subcutaneo us injections) br placebo in 60 patients with psoriatic arthritis and psori asis. Psoriatic arthritis endpoints included the proportion of patients who met the Psoriatic Arthritis Response Criteria (PsARC) and who met the Amer ican College of Rheumatology preliminary criteria for improvement (ACR20). Psoriasis endpoints included improvement in the psoriasis area and severity index (PASI) and improvement in prospectively-identified individual target lesions. Findings in this 12 week study, 26 (87%) of etanercept treated patients met the PsARC, compared with seven (23%) of placebo-controlled patients. The A RC20 was achieved by 22 (73%) of etanercept-treated patients compared with four (13%) of placebo-treated patients. Of the 19 patients in each treatmen t group who could be assessed for psoriasis (greater than or equal to 3% bo dy surface area), five (26%) of etanercept-treated patients achieved a 75% improvement in the PASI, compared with none of the placebo-treated patients (p=0.015). The median PASI improvement was 46% in etanercept-treated patie nts versus 9% in placebo-treated patients; similarly, median target lesion improvements were 50% and 0, respectively. Etanercept was well tolerated. Interpretation Etanercept offers patients with psoriatic arthritis and psor iasis a new therapeutic option for control of their disease.