Hyperion Therapeutics, Inc announced that its investigational product HPN-100 (glycerol phenylbutyrate) has received orphan product designation from the US Food and Drug Administration for intermittent or chronic treatment of patients with cirrhosis and any grade of hepatic encephalopathy. The company is planning to initiate a phase-II clinical programme in this indication later this year.

HPN-100 (glycerol phenylbutyrate), an investigational product, is a pre-pro-drug of phenylacetic acid, the active moiety of Buphenyl, the only therapy currently FDA-approved as adjunctive therapy for the chronic management of patients with the most prevalent urea cycle disorders: carbamylphosphate synthetase (CPS), ornithine transcarbamylase (OTC), and argininosuccinic acid synthetase (AS) deficiencies.

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).

Hyperion Therapeutics is a privately held specialty therapeutics company focused on the development of therapies that address critical unmet needs and underserved patient populations in the areas of gastroenterology and hepatology.