SOUTH SAN FRANCISCO, Calif., June 3, 2013 (GLOBE NEWSWIRE) -- Hyperion Therapeutics, Inc. (Nasdaq:HPTX) today announced the completion of its acquisition of BUPHENYL® (sodium phenylbutyrate) Tablets and Powder, an FDA-approved therapy for treatment of the most prevalent urea cycle disorders (UCD), from Ucyclyd Pharma Inc., a subsidiary of Valeant Pharmaceuticals International, Inc. (NYSE:VRX) (TSX:VRX). As part of this transaction, Hyperion received a net payment of approximately $11 million due to Ucyclyd's exercise of its option to retain AMMONUL® (sodium phenylacetate and sodium benzoate) Injection 10%/10%, a hospital-based product used for the treatment of acute hyperammonemia in UCD patients. Hyperion was granted an option to acquire both BUPHENYL and AMMONUL under a March 2012 collaboration agreement between Hyperion and Ucyclyd Pharma Inc. However as part of the agreement, Ucyclyd had an option to retain AMMONUL. The net payment to Hyperion reflects the $19 million purchase price for BUPHENYL due to Ucyclyd and a $32 million payment due to Hyperion as a result of Ucyclyd's exercise of its option to retain AMMONUL, less costs of approximately $2 million in inventory due to Ucyclyd. According to Donald J. Santel, Hyperion's chief executive officer, "RAVICTI™ (glycerol phenylbutyrate) Oral Liquid remains the cornerstone of our commercial plan. However, the addition of BUPHENYL to our commercial product portfolio affords us an opportunity to serve the entire UCD patient population, including those under two years of age. BUPHENYL patients will also have access to our comprehensive patient assistance programs administered via Hyperion UCD Support Services." About BUPHENYL (sodium phenylbutyrate) Tablets and Powder BUPHENYL is indicated as adjunctive therapy in the chronic management of patients with urea cycle disorders involving deficiencies of carbamylphosphate synthetase (CPS), ornithine transcarbamylase (OTC), or argininosuccinic acid synthetase (AS). BUPHENYL should not be administered to patients with known hypersensitivity to sodium phenylbutyrate or any component of this preparation. The most common adverse reactions associated with BUPHENYL were amenorrhea dysfunction, decreased appetite, body odor (probably caused by its metabolite phenylacetate) and bad taste or taste aversion. Patients with urea cycle disorders should not take valproic acid, haloperidol, or steroids as these drugs have been reported to increase blood ammonia levels, and probenecid may affect the kidneys' excretion. Use with great care, if at all, in patients with congestive heart failure or severe renal insufficiency, and in clinical states where there is sodium retention with edema. Use caution when administering to patients with hepatic or renal insufficiency or inborn errors of beta oxidation. The safety or efficacy of doses in excess of 20 grams (40 tablets) per day has not been established.