In the case of orphan drugs, economic evaluation within the health technology assessment framework may (e.g. in England and Wales, Scotland, the Netherlands or Sweden) or may not (e.g. in France or Belgium) be applied (Denis et al. 2009; Denis et al. 2010). Ideally, the health technology assessment process to guide the coverage decision of an orphan drug should consider multiple criteria that reect the specic characteristics of orphan drugs (see below). Such decision-making criteria may include the rarity and the severity of the disease (i.e. the unmet need), the availability of alternative health technologies, the impact of the orphan drug on the disease (i.e. whether the drug’s objective is symptomatic, palliative, or to modify the disease), the use of an orphan drug in a single or in multiple indications, the level, quality and uncertainty of clinical evidence and research undertaken, and the manufacturing complexity involved in producing the orphan drug (Hughes-Wilson et al. 2012).