In contrast to traditional drugs, orphan drugs do not require the definition of an appropriate comparative therapy to determine the extent of the additional benefit. The study data relevant for the approval are used for the benefit assessment. This is partly due to the fact that in the case of rare diseases there is often no appropriate comparative therapy in the approved indication. However, there are exceptions to the exception: if the turnover of a drug for a rare disease exceeds 50 million euros within a year in the outpatient sector, a classical benefit assessment is initiated, which is based on the criteria for innovative drugs, in particular in comparison to an appropriate comparative therapy. With a sales volume of more than 50 million euros, a new benefit assessment is therefore carried out, which also leads to new price negotiations.
The extent of the added value of orphan drugs is assessed according to the categories significant, significant, low and non-quantifiable. In the past, it has been shown that most orphan drugs fall into the category „unquantifiable“. This ultimately expresses that in many cases the data situation according to the criteria of evidence-based medicine is not sufficient to describe the extent of the additional benefit.