OBJECTIVES: In order to stimulate the research and development of orphan drugs, in 2000 the EU introduced new legislation with the aim of providing incentives for the development of drugs for rare disorders. One of the strongest incentives, regarding experience in the United States of America and Japan, is a market exclusivity period post authorization for designated products. The objective of this study is to assess if the 10 year market exclusivity has created a market failure by assessing the prices and the competition environment of drugs for which this period has come to an end. METHODS: From the 2014 Orphanet’s list, we retrieved the 20 drugs that have lost their market exclusivity for at least one indication (26 indications). It is worth to note that some of them still have market exclusivity for another indication, which means they may still be on the orphan drug register. We focused on the French market and used French administrated prices. RESULTS: