Availability of and access to orphan drugs: an international comparison of pharmaceutical treatments for pulmonary arterial hypertension, Fabry disease, hereditary angioedema and chronic myeloid leukaemia.

摘要

BACKGROUND: Market authorization does not guarantee patient access to any given drug. This is particularly true for costly orphan drugs because access depends primarily on co-payments, reimbursement policies and prices. The objective of this article is to identify differences in the availability of orphan drugs and in patient access to them in 11 pharmaceutical markets: Australia, Canada, England, France, Germany, Hungary, the Netherlands, Poland, Slovakia, Switzerland and the US. METHODS: Four rare diseases were selected for analysis: pulmonary arterial hypertension (PAH), Fabry disease (FD), hereditary angioedema (HAE) and chronic myeloid leukaemia (CML). Indicators for availability were defined as (i) the indications for which orphan drugs had been authorized in the treatment of these diseases; (ii) the application date; and (iii) the date upon which these drugs received market authorization in each country. Indicators of patient access were defined as (i) the outcomes of technology appraisals; (ii) the extent of coverage provided by healthcare payers; and (iii) the price of the drugs in each country. For PAH we analysed bosentan, iloprost, sildenafil, treprostinil (intravenous and inhaled) as well as sitaxentan and ambrisentan; for FD we analysed agalsidase alfa and agalsidase beta; for HAE we analysed icatibant, ecallantide and two complement C1s inhibitors; for CML we analysed imatinib, dasatinib and nilotinib. RESULTS: Most drugs included in this study had received market authorization in all countries, but the range of indications for which they had been authorized differed by country. The broadest range of indications was found in Australia, and the largest variations in indications were found for PAH drugs. Authorization process speed (the time between application and market authorization) was fastest in the US, with an average of 362 days, followed by the EU (394 days). The highest prices for the included drugs were found in Germany and the US, and the lowest in Canada, Australia and England. Although the prices of all of the included drugs were high compared with those of most non-orphan drugs, most of the insurance plans in our country sample provided coverage for authorized drugs after a certain threshold. CONCLUSIONS: Availability of and access to orphan drugs play a key role in determining whether patients will receive adequate and efficient treatment. Although the present study showed some variations between countries in selected indicators of availability and access to orphan drugs, virtually all of the drugs in question were available and accessible in our sample. However, substantial co-payments in the US and Canada represent important barriers to patient access, especially in the case of expensive treatments such as those analysed in this study. Market exclusivity is a strong instrument for fostering orphan drug development and drug availability. However, despite the positive effect of this instrument, the conditions under which market exclusivity is granted should be reconsidered in cases where the costs of developing an orphan drug have already been amortized through the use of the drug's active ingredient for the treatment of a common indication.