SOUTH SAN FRANCISCO, Calif.--(BUSINESS WIRE)--Hyperion Therapeutics, Inc. today announced that the Company’s phase III pivotal study of glycerol phenylbutyrate (HPN-100), an investigational drug for the treatment of urea cycle disorders (UCDs), met its primary endpoint. The non-inferiority study, conducted under a Special Protocol Assessment (SPA) granted by the U.S. Food and Drug Administration (FDA) in June 2009, evaluated the ammonia control of glycerol phenylbutyrate as compared to sodium phenylbutyrate (BUPHENYL®).
