Persistence and cost of biologic agents for psoriasis: Retrospective study in the balearic islands

Objectives: The aim of this study was to assess the drug survival rate (persistence rate) and to evaluate the efficiency in terms of cost per persistence for etanercept (ETN), adalimumab (ADA) and ustekinumab (UST) in a real clinical setting of five Hospitals in the Balearic Islands (Spain). Method: A retrospective observational multicentric study was designed, in which only biological naive patients, with six or more months with biologic treatment were included. It was incorporated data since January 1st, 2010 until December 31st, 2013. The evaluated variables were: sex, weight, age, arthritis, reasons of discontinuation, dates of dispensation and quantity. Costs were estimated based on the purchase cost (average wholesale price), estimating annual cost according to the first treatment received. Persistence rates were reckoned taking into account the current total days of therapy comparing posology with supplied dose. It was estimated with the method of Kaplan-Meier. Results: We have evaluated a cohort of 112 psoriasis patients, of which 57% were men. 37 patients started treatment with ADA, 34 with ETN and 41 with UST. The persistence rate at two years was, 48% for ADA, 62% for ETN and 81% for UST. The cost per persistence at two years was 52,961 € for ADA, 40,160 € for ETN, and 30,657 € for UST. Conclusions: Based on the results obtained in our study, and until long-term data on the use of UST become available, the most cost-effective option for a treatment-naive patient for the medium term would be to start treatment with UST