Hyperion Therapeutics has won approval for its urea cycle disorder (UCD) drug Ravicti in the US and says it plans to launch the product by the end of April.
Tipped as a $250m product at peak, Ravicti (glycerol phenylbutyrate) is designed to tackle the toxic effects of excess ammonia in the body and will be Hyperion’s first commercialised drug.
UCD is a group of inherited rare genetic diseases that can be fatal in their most severe form if left untreated, and occur in around 1 in 10,000 births in the US.
Normally, when protein is broken down by the body it produces nitrogen as a waste product, which is removed from the blood, converted to urea and excreted in urine. In people with UCDs, nitrogen accumulates in the body as ammonia, which is highly neurotoxic.
Hyperion has been given the go-ahead by the FDA to market Ravicti for the treatment of patients aged two years or over. At the moment UCD patients are managed via protein-restricted diets, amino acid supplements and older ammonia-lowering agents such as sodium benzoate and Swedish Orphan’s Buphenyl (sodium phenylbutyrate), although Hyperion claims compliance with these older drugs is poor.
Ravicti was reviewed and approved under the FDA’s fast-track programme, largely on the back of a crossover study in 44 adult patients who switched between Ravicti and Buphenyl treatment.
Blood testing showed Ravicti was as effective as Buphenyl in controlling ammonia levels, while three additional studies in children and adults provided evidence supporting the long-term safety and effectiveness of Hyperion’s drug.
In addition to its role in UCD, Ravicti could also have upside potential in other indications such as hepatic encephalopathy, a neurological disorder that can occur in patients with liver disease who represent a much larger patient population.
News of the approval led to a 33 per cent surge in Hyperion’s share price to $21.05, well above its 52-week high of $16.48.