Shire plc announced that the U.S. FDA has granted Breakthrough Therapy Designation for two investigational products for rare diseases: SHP621 (budesonide oral suspension, or BOS) for eosinophilic esophagitis (EoE), and SHP625 (maralixibat) for progressive familial intrahepatic cholestasis type 2 (PFIC2).

BOS is a novel, topically active, oral viscous formulation of budesonide. BOS is formulated specifically for EoE.  EoE is a serious, chronic and rare disease that stems from an elevated number of eosinophils, a type of white blood cell, that infiltrate the walls of the esophagus. EoE is characterized by an inflammation of the esophagus that may lead to difficulty swallowing (dysphagia). The diagnosed prevalence of EoE ranges from approximately 15-55 cases per 100,000 persons, with high-end estimates reported by studies in Western regions.

Maralixibat (LUM001) is being evaluated in several rare cholestatic liver diseases for both pediatric and adult populations.