Economic evaluation of etanercept in the management of chronic plaque psoriasis.

BACKGROUND The National Institute for Health and Clinical Excellence has recommended that etanercept 25 mg twice weekly (biw) be used in adults with severe plaque psoriasis. However, its economic model did not consider the alternative licensed regimen of etanercept 50 mg biw. OBJECTIVES To assess the cost-effectiveness of etanercept 50 mg biw for the treatment of chronic plaque psoriasis, and to explore characteristics of patients who benefited most from 50 mg dosing. METHODS An economic model was constructed to estimate the incremental cost per quality-adjusted life year (QALY) gained. The model considered patients with chronic plaque psoriasis who had both Psoriasis Area and Severity Index (PASI) and Dermatology Life Quality Index (DLQI) of 10 or higher who were unable to take standard systemic therapies. Quality of life gain was estimated from the DLQI responses of patients enrolled in three clinical studies. The model considered expenditure on drugs, monitoring visits, adverse events and inpatient stays. Costs were estimated from the perspective of the U.K. National Health Service over a time period of 10 years. RESULTS The incremental cost per QALY for etanercept 50 mg biw compared with no systemic therapy was found to be 6217 pounds sterling (95% confidence interval 5396-7486 pounds sterling). The cost-effectiveness of 50 mg dosing was more attractive in patients with baseline PASI > or = 20 (5163 pounds sterling) or baseline DLQI > or = 20 (4599 pounds sterling). CONCLUSIONS This model found the licensed dose regimen of etanercept 50 mg biw to be cost effective in the U.K. This regimen was particularly appropriate for patients with severe disease or poor quality of life at baseline.