Orphan Designation for Drugs Approved in the United States and European Union: A Comparative Analysis

The US Orphan Drug Act and EU Orphan Regulation both offer incentives to develop rare disease treatments, but of 344 rare disease drug indications approved from 2011 to 2020, 97.7% received FDA Orphan Drug designation versus only 40.4% from the EMA, with the agencies aligning most on advanced therapies and genetic diseases but diverging on cancer subsets and pediatric indications of common diseases like HIV. These differences reflect the broader US indication-based framework versus the EU’s narrower focus on distinct conditions, suggesting policymakers should target incentives toward truly rare diseases rather than subsets of common conditions like cancer.