Urea Cycle Disorders


Urea Cycle Disorders – hepatic opportunity

  • UCDs: a family of metabolic disorders with devastating patient consequences
  • Each results from an inherited single-gene deficiency
  • Hyperammonemia causes cumulative and irreversible neurologic impairment, coma and death
  • Liver transplant is the only current cure
  • The only drug treatment, ammonia scavengers, is palliative at best
  • PhaseRx plans to deliver mRNA, encoding the missing protein and correcting the disease

Our mRNA therapeutics for urea cycle disorders, administered intravenously, are intended to provide delivery of mRNA encoding the missing enzyme into the liver cell. Administration of the mRNA allows the patient to produce the needed enzyme and corrects the disease.


Because our approach addresses the underlying cause of the disease by reinstating the normal physiology, it is anticipated that no dietary restriction or special amino acid supplementation will be necessary, and the disease can be managed without crisis or continued neurologic deterioration. For all of our urea cycle disorder programs, the product profile of our candidates is anticipated to include reversal of the enzyme deficiency, which would be expected to correct the disorder by restoring the normal physiology, and normalize plasma ammonia levels, eliminate the dietary restrictions, and eliminate hyperammonemic crises.