SOUTH SAN FRANCISCO, Calif., April 16, 2013 (GLOBE NEWSWIRE) -- Hyperion Therapeutics, Inc. (Nasdaq:HPTX) today announced that the U.S. Patent & Trademark Office (USPTO) has issued to Hyperion U.S. patent number 8,404,215 entitled, METHODS OF THERAPEUTIC MONITORING OF NITROGEN SCAVENGING DRUGS. The patent discloses optimal measurement timing and target levels for blood ammonia in urea cycle disorder (UCD) patients. The issued patent has a term that expires in March 2032. Hyperion plans to list this patent in the FDA's Approved Drug Products with Therapeutic Equivalence Evaluations, known as the Orange Book. Hyperion announced on February 2, 2013, the allowance of its patent application by the USPTO.

RAVICTI Indications, Usage and Safety Information

RAVICTI is indicated for use as a nitrogen-binding agent for chronic management of adult and pediatric patients ≥ two years of age with UCD that cannot be managed by dietary protein restriction and/or amino acid supplementation alone. RAVICTI must be used with dietary protein restriction and in some cases, dietary supplements (e.g. essential amino acids, arginine, citrulline, protein-free calorie supplements).

Limitations of Use:

• RAVICTI is not indicated for the treatment of acute hyperammonemia (HA) in patients with UCD because more rapidly acting interventions are essential to reduce plasma ammonia levels.
• The safety and efficacy of RAVICTI for the treatment of N-acetylglutamate synthase (NAGS) deficiency has not been established.

RAVICTI is Contraindicated in Patients:

• Less than two months of age. Children less than two months of age may have immature pancreatic exocrine function which could impair hydrolysis of RAVICTI, leading to impaired absorption of phenylbutyrate and HA.
• With known hypersensitivity to phenylbutyrate. Signs of hypersensitivity include wheezing, shortness of breath, coughing, low blood pressure, flushing, nausea and rash.

The major metabolite of RAVICTI, PAA, is associated with neurotoxicity at levels ≥ 500 μg/mL. If symptoms of vomiting, nausea, headache, drowsiness, or confusion are present in the absence of high ammonia or other intercurrent illnesses, reduce the RAVICTI dosage.

Pancreatic insufficiency or intestinal malabsorption may result in reduced or absent digestion of RAVICTI and/or absorption of phenylbutyrate and reduced control of plasma ammonia. Monitor ammonia levels closely in these patients.

Most common adverse reactions in 10% or more of patients are: diarrhea, flatulence, headache, nausea, vomiting, fatigue, decreased appetite, HA, dizziness, headache, upper abdominal (stomach) pain and rash.

Corticosteroids, valproic acid, or haloperidol may increase plasma ammonia levels; monitor ammonia levels closely when used concomitantly with RAVICTI. Probenecid may affect renal excretion of metabolites of RAVICTI including PAGN and PAA.

The use of RAVICTI in pregnant women may cause fetal harm. Breastfeeding is not recommended during RAVICTI treatment.

Please see full Prescribing Information for RAVICTI at www.hyperiontx.com.

About Hyperion Therapeutics

Hyperion Therapeutics, Inc. is a commercial stage biopharmaceutical company committed to developing and delivering life-changing treatments for orphan diseases and hepatology.