Wellstat Therapeutics Corporation, a privately-held biopharmaceutical company located in Gaithersburg, MD, announced that the U.S. FDA has approved XURIDEN™ (uridine triacetate) for the treatment of hereditary orotic aciduria (HOA). HOA is a rare genetic disorder caused by mutations in the gene encoding uridine monophosphate synthase (UMPS), which is responsible for converting orotic acid to UMP, an important metabolic molecule involved in many biosynthetic pathways. Insufficient UMPS leads to excessive excretion of orotic acid in urine, resulting in urinary tract obstruction due to orotic acid crystal formation in the urinary tract, various blood abnormalities and development delays. XURIDEN is a pyrimidine analog intended to provide patients with adequately uridine to restore intracellular uridine concentration and normalize orotic acid concentration. The safety and efficacy of XURIDEN are supported by a clinical trial involving four patients. This is the first FDA-approved therapy for HOA.