What Makes an Orphan Medicine? Determining Characteristics of Non-Oncology Orphan Approvals from 2015-2022

OBJECTIVES: The FDA defines orphan medicines as those treating diseases with a prevalence <200,000 or which will not be profitable within 7 years following approval. However, there is no tracking system which summarizes the actual significant characteristics (e.g., prevalence, price, route of administration) of approved orphan medicines in detail. This research aims to understand the characteristics and attributes of recently approved orphan medicines.

METHODS: We referenced the CDER database to collect all new FDA approvals from 2015-2022. Approvals were then checked against the orphan medicine database, with all non-orphan products removed. Some products were excluded from analysis due to exceptional circumstances (e.g., humanitarian applications). To control for the unique attributes of oncology, we removed all oncology medicines. We then referenced secondary sources to collect the launch WAC, prevalence, typical treatment duration (acute or chronic), route of administration, and number of FDA-approved alternatives for each product. We also calculated the annual per patient price using launch WAC.

RESULTS: n=76 orphan medicines met screening criteria for analysis. 55% of medicines were ultra-orphan (prevalence <1/50,000), and 45% were not. Annual per patient prices were distributed accordingly: 21% <$100k; 22% $100k-$250k; 33% $250k-$500k; 17% $500k-$1M; and 7% >$1M. 91% of products were for chronic use and 9% were for limited durations of treatment. 55% were first in indication therapies. The average number of indicated competitors for the 45% of products which were not first in indication was 2. Most products were orals (41%), followed by IVs (30%), subcutaneous products (28%), and topicals (1%); accordingly, most products (65%) were self-administered.

CONCLUSIONS: The recent focus on orphan drug development has resulted in a remarkably varied set of therapies which reflect the drug market at large. The orphan drug pathway remains an attractive development route for manufacturers regardless of product attributes.