GAITHERSBURG, MD, USA I September 8, 2015 I Wellstat Therapeutics Corporation announced today that on September 4, 2015, the US Food and Drug Administration granted marketing approval for XURIDEN™ (uridine triacetate), a pyrimidine analog for uridine replacement indicated for the treatment of hereditary orotic aciduria (HOA). With the approval of XURIDEN for the treatment of HOA, the FDA also granted Wellstat Therapeutics a Rare Pediatric Disease Priority Review Voucher. HOA is an extremely rare, potentially life-threatening, genetic disorder in which patients cannot synthesize adequate amounts of uridine and consequently can suffer from hematologic abnormalities, failure to thrive, a range of developmental delays, and episodes of crystalluria leading to obstructive uropathy.

“The approval of XURIDEN and the granting of a Rare Pediatric Disease Priority Review Voucher are significant milestones for Wellstat Therapeutics Corporation,” said Samuel J. Wohlstadter, CEO. “The FDA’s dedication to encouraging companies to make treatments available for patients with rare pediatric diseases has been evident throughout the development of XURIDEN, and this approval and voucher grant highlight that commitment.”

Michael K. Bamat, Ph.D., Vice President of Research and Development said, “The FDA’s approval of XURIDEN for hereditary orotic aciduria is an important breakthrough for patients with this rare, potentially life-threatening orphan disease and for their families. There have been no approved treatments for these patients until now.”

In September 2014, Wellstat entered into an agreement with AstraZeneca under which the Pediatric Priority Review Voucher would be transferred to AstraZeneca upon approval. Financial terms of the agreement have not been disclosed.

Wellstat anticipates that XURIDEN will be commercially available in early 2016.

About HOA

Hereditary orotic aciduria (HOA) is a genetic disorder caused by mutations reducing the activity of uridine monophosphate synthase (UMPS), which converts orotic acid to UMP. Uridine deficiency underlies many of the symptoms of HOA, including hematologic abnormalities, developmental delays, failure to thrive, and if untreated, early mortality. Orotic acid biosynthesis is normally subject to feedback inhibition by intracellular uridine nucleotides and is therefore overproduced in HOA. The resulting increased levels of orotic acid can cause crystalluria and occasional obstructive uropathy.

The goal of uridine replacement therapy in HOA is to provide the uridine that these patients cannot make adequately themselves in order to restore intracellular uridine nucleotide concentrations, enabling and supporting the biosynthetic functions of pyrimidine nucleotides and their derivatives, and also normalizing orotic acid production.


XURIDEN is a pyrimidine analog for uridine replacement indicated for the treatment of hereditary orotic aciduria. Oral administration of XURIDEN delivers 4 to 7 times more uridine than oral administration of uridine itself.

Important Safety Information

  • Contraindications – None
  • Warning and Precautions – None
  • Adverse reactions – No adverse reactions were reported with XURIDEN in patients with HOA.
  • Pregnancy – There are no available data on XURIDEN use in pregnant women to inform drug-associated risk.
  • Lactation – There are no data on the presence of XURIDEN in human milk, the effect on the breast-fed infant or the effect on milk production. The development and health benefits of breastfeeding should be considered along with the mother’s clinical need for XURIDEN and any potential adverse effects on the breastfed infant from XURIDEN or from the underlying maternal condition.
  • Pediatric – The safety and effectiveness of XURIDEN have been established in pediatric patients.

For the full Prescribing Information go to

About Wellstat Therapeutics

Wellstat Therapeutics Corporation is a privately-held biopharmaceutical company located in Gaithersburg, Maryland. Wellstat Therapeutics is committed to discovering, developing and commercializing products that will provide new and improved treatments for patients in the fields of oncology and metabolic, neurometabolic and neurodegenerative diseases. Wellstat Therapeutics is part of the Wellstat group of companies, For more information, please visit the website at

SOURCE: Wellstat Therapeutics