Orphan medicinal products (OMPs) are medicines used to prevent, diagnose or treat rare medical conditions and diseases. Given that the number of patients affected is very low, in the absence of incentives, pharmaceutical companies may be uncertain whether they could recover, through sales, the costs of research and development (R&D) of medical products to diagnose, prevent and treat these rare diseases. 'Rare' is defined in the relevant EU legislation as affecting less than five in 10,000 people in the EU. However, most rare diseases affect less than one in 100,000 people. Despite the low prevalence of individual rare diseases, they are of significant public health importance. There are estimated to be over 6,000 rare diseases, so while individually rare, collectively they represent a significant number of patients, amounting to approximately one in every 12 people in the EU (all rare diseases combined). Without incentives, it is often not commercially viable for pharmaceutical companies to develop and market OMPs, and only around 5% of rare diseases have an authorised treatment option. Based on