Clinical trials on rare diseases in Austria 2011-2021: a study using the orphanet database

A majority of the more than 6,500 rare diseases known today still lack specific therapeutic options. Low numbers of patients and consequently participants in clinical studies, as well as high costs of development in relation to return on investment have hindered pharmaceutical companies in the development of rare disease therapeutics. However, regulatory incentives and a number of international initiatives are promoting the orphan medicine market and clinical research on rare diseases to grow quickly. We collected data on clinical trials and observational studies for rare diseases in Austria for the decade between 2011 and 2021 using the Orphanet database. Our aim was to explore the development of clinical research on rare diseases during this pivotal decade with prominent advances in the field, using the Austrian data as an example for a small-to-medium-sized European country with a highly developed healthcare system.

We performed a systematic search in three large clinical study registers (the EU Clinical Trials Register, the ClinicalTrials.gov database of the National Institutes of Health, and the German Clinical Trials Register), entered the data in the Orphanet database and analysed them with regard to numbers, types of trials, rare diseases included, and medicinal products used.

Our results show that the numbers of clinical trials on rare diseases have been rising steadily, with the most prominent fields being rare cancers, followed by rare autoimmune and autoinflammatory diseases. The most notable growth rates in therapeutic development strategies were seen for monoclonal antibodies, while small molecules, including the large group of kinase inhibitors, are the most frequently used products overall. Trials using advanced therapy medicinal products were still scarce in comparison.

Taken together, clinical research in the rare disease field is increasing profoundly. While medicinal products targeting genetic diseases are still scarce, especially monoclonal antibodies are increasingly used in clinical trials on rare diseases, in addition to small molecule drugs. A profoundly different picture of clinical research on rare diseases and of the orphan medicine landscape can be expected in the following decade.