OBJECTIVES : Mucopolysaccharidosis type II (MPS II) is a rare metabolic disease. Enzyme replacement therapy (ERT) of idursulfase and idursulfase beta is the only approved treatment for patients with MPS II type. Idursulfase beta is a newly registered drug produced by cell line sources are chinese hamster ovary. A simulated strategy suggested switching patients from idursulfase to idursulfase beta, because in the local market idursulfase beta is more affordable drug, which can save budget funds in a limited health system budget. The aim of the study was to budget impact analysis (BIA) introducing of idursulfase beta compared with idursulfase during ERT of MPS II.

METHODS : A simulation model with 5 year time horizon. The total number of patients with MPS II in Russia estimated of 133, receiving ERT is 108 (children and adults). Only direct costs were included: treatment of complications, ERT, correction of side effects, drug administration. According to literature data evidence is no difference in efficacy between drugs. The exchange rate was EUR 1 = 72 RUB.

RESULTS : The total costs of a course of treatment MPS II patients with an average weight of 40 kg of idursulfase beta is EUR 393 873 per patient per year, of idursulfase is EUR 496 342 per patient per year. When we simulated gradual switching of patients through 5 years up to 50% of patients to idursulfase beta, cost savings of EUR 11 067 295 is obtained.

CONCLUSIONS : The results of the BIA demonstrated that gradual switching in 5 year period from idursulfase to idursulfase beta will lead to 4,21% budget savings of the MPS II treatment in the Russian Federation.