Hyperion Therapeutics drug gets FDA orphan status

SOUTH SAN FRANCISCO, Calif. (AP) -- Hyperion Therapeutics Inc. said Thursday that its drug Ravicti received orphan drug status, giving the drug seven years of marketing exclusivity.

Ravicti was approved Feb. 1 as a treatment for urea cycle disorders, a rare type of enzyme deficiency, in patients 2 years and older. The Food and Drug Administration's decision to grant orphan drug status will keep similar products off the market until Feb. 1, 2020.

Urea cycle disorders are genetic conditions caused by deficiency in an enzyme that removes ammonia from the bloodstream. That deficiency causes ammonia to build up in the patient's bloodstream.

Separately, Hyperion said it exercised options to acquire the rights to two other urea cycle disorder treatments from Valeant Pharmaceuticals Inc. The company said the drug Buphenyl is used to treat the disorders themselves, while Ammonul is used to treat hospitalized patients whose ammonia levels have become dangerously high.

Hyperion said Valeant has 20 days to notify it if it wants to retain Ammonul. If Valeant decides to keep the drug, it will pay Hyperion $13 million. If Valeant decides not to retain the drug, Hyperion will pay Valeant $22 million. Hyperion said it expects the deals to close by May 29.

Shares of Hyperion rose $1.76, or 8.8 percent, to $21.76 in afternoon trading. They have traded in a 52-week range of $9.95 to $26.50.