Horizon Pharma plc (NASDAQ:HZNP) has submitted a supplemental New Drug Application (sNDA) with the U.S. Food and Drug Administration (FDA) to expand the approved indication for RAVICTI (glycerol phenylbutyrate) Oral Liquid to include infants younger than two months of age living with urea cycle disorders (UCDs).
Currently, RAVICTI is indicated for use as a nitrogen-binding agent for chronic management of adult and pediatric patients greater than two months of age with UCDs who cannot be managed by dietary protein restriction and/or amino acid supplementation alone. RAVICTI is not indicated for treatment of acute hyperammonemia in patients with UCDs, and the safety and efficacy of RAVICTI for the treatment of n-acetylglutamate synthase (NAGS) deficiency has not been established. The sNDA seeks to expand RAVICTI’s indication to include an age range down to birth, and is based on an open-label clinical study evaluating 16 patients with UCDs less than two months of age. The FDA is expected to complete their review during the second half of 2018.
“Urea cycle disorders are typically most severe when the onset of symptoms begin early in life, and symptoms that begin right after birth are particularly challenging,” said Shao-Lee Lin, M.D., Ph.D., executive vice president, head of research and development and chief scientific officer, Horizon Pharma plc. “As part of Horizon’s ongoing effort to reinvest in our medicines, this sNDA submission brings us closer to achieving our mission to make RAVICTI available for the majority of those living with a UCD, including newborns.”
A UCD is a rare genetic disorder that affects approximately 1 in 35,000 live births in the United States. It is caused by an enzyme deficiency in the urea cycle, a process that is responsible for converting excess ammonia from the bloodstream and ultimately removing it from the body. Because of this, people with a UCD experience hyperammonemia, or elevated ammonia levels in their blood, that can then reach the brain and cause irreversible brain damage, coma or death. UCD symptoms may first occur at any age depending on the severity of the disorder, with more severe defects presenting earlier in life.