Table 1 Orphan diseases and OMPs

The European Commission is responsible for authorizing OMPs in the European Union (EU), after careful evaluation of the OMP’s benefits and risks by the European Medicines Agency. An OMP is a drug that is indicated for the treatment of a rare disease with a prevalence of < 5:10000. A centralized procedure allows applicants to obtain a marketing authorization that is valid throughout the EU as well as in the European Economic Area, and is compulsory for the authorization of OMPs and medicines containing a new active substance to treat cancer [64]. Marketing authorizations may be ‘full’ (sufficient comprehensive data are available), ‘conditional’ (benefit of immediate authorization outweighs the risk of less comprehensive data than normally required, but additional data are expected to be generated in the future) or ‘exceptional’ (authorization is granted even though comprehensive data are not expected to be obtained after authorization) [65].