South San Francisco, CA - July 22, 2008 - Hyperion Therapeutics, Inc. today announced that it has completed patient enrollment in its Phase 1/2 clinical trial to evaluate the safety, tolerability and ammonia scavenging effects of HPN-100 (formally called GT4P) versus BUPHENYL® (sodium phenylbutyrate) in patients with urea cycle disorders (UCD). The company plans to announce top-line results in the fourth quarter of this year.
“Completing enrollment in this Phase 1/2 study is an important milestone in our development program," said Bruce Scharschmidt, Chief Medical Officer of Hyperion Therapeutics. “This represents the first trial of HPN-100 in patients with UCDs and the results will be important in assessing its potential to improve care for these patients.”
About Urea Cycle Disorder
UCDs are inherited, inborn errors of metabolism present in an estimated 1 in 10,000 births in the US. Patients with UCDs lack or are deficient in one of the key enzymes that comprise the urea cycle, the body’s primary vehicle for removing ammonia, a potent neurotoxin, from the bloodstream. UCDs often present in the neonatal period, but onset can occur at any age depending on the severity of the disorder. Left untreated, UCDs can cause dangerously heightened levels of ammonia in the bloodstream (hyperammonemia) resulting in brain damage, coma, and/or death.
HPN-100 is a pro-drug of phenylbutryrate and a pre-pro-drug of phenylacetic acid (PAA), 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). HPN-100, which is dosed orally in liquid form, provides an alternative pathway to the urea cycle for the disposal of waste nitrogen through the renal excretion of phenylacetylglutamine, which is formed from PAA and glutamine.
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.
About Hyperion Therapeutics
Hyperion Therapeutics is a specialty therapeutics company focused on the development of therapies that address orphan or underserved patient populations with unmet medical needs. Hyperion is headquartered in South San Francisco, CA. For additional information, visit: www.hyperiontx.com.
Hyperion Therapeutics, Inc.