RARE Act

This bill amends rules for orphan drug exclusivity under U.S. drug law. It changes the definition of "rare disease or condition" to specifically refer to the "approved use or indication" for which a drug was initially approved. This means exclusivity periods now apply to specific medical uses (e.g., treating a particular symptom of a rare disease), not just the broad disease name. The change affects drug manufacturers developing new treatments for rare diseases and the FDA in evaluating exclusivity claims, applying to all drugs designated under current law regardless of when they were approved.