South San Francisco, CA - October 23, 2007 - Hyperion Therapeutics, Inc. today announced that the first patient has been enrolled in a Phase 1/2 clinical trial of Glyceryl Tri (4-Phenylbutyrate) (GT4P) in patients with urea cycle disorders (UCDs).
“UCDs are complex disorders which require a multi-faceted management approach, including a protein restricted diet, amino acid supplementation, and pharmacological therapy,” said Brendan Lee, M.D., Ph.D. the first investigator to enroll a patient in the GT4P Phase 1/2 trial and Professor, Department of Molecular and Human Genetics at Baylor College of Medicine. “We look forward to seeing the results from the clinical trials of GT4P in the management of UCDs.”
The phase 1/2 study is designed to evaluate the safety, tolerability and ammonia scavenging effects of GT4P compared to BUPHENYL® (sodium phenylbutyrate) in patients with UCDs. A total of up to ten adults with stable UCD will be included in the trial which is being conducted at US-based clinical sites. Estimated duration of treatment is 3 to 4 weeks.
“We are very excited about our research of GT4P focused on the chronic management of urea cycle disorders,” said Marvin Garovoy, Senior Vice President of Clinical Development of Hyperion Therapeutics, Inc. “Initiation of this trial marks the beginning of several Hyperion clinical programs aimed at developing new therapies for hepatic disease.”
GT4P is composed of a glycerol backbone covalently attached via ester linkages to three molecules of phenylbutyrate. It is a prodrug of BUPHENYL® (a currently FDA-approved 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)), and a pre-prodrug of phenylacetate (PAA).
About Urea Cycle Disorder
A urea cycle disorder is an inherited, inborn error of metabolism present in an estimated 1 in 10,000 live births in the U.S. 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. The age of onset of UCDs is typically 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.
There is no cure for UCDs. Adherence to a low-protein diet is a key component to chronic disease management. Current therapies include arginine supplementation, which drives functional parts of the urea cycle, essential amino acid supplementation, replacement of urea cycle intermediates, and administration of nitrogen-scavenging drugs including BUPHENYL® for chronic disease management and AMMONUL® (sodium phenylacetate and sodium benzoate) Injection 10%/10% for episodes of acute hyperammonemia. Orthotopic liver transplantation may also be considered for patients with severe disease.
About Hyperion Therapeutics
Hyperion Therapeutics is a specialty therapeutics company focused on becoming a global leader in gastrointestinal (GI) and hepatology therapeutic programs and products that address underserved patient populations or unmet medical needs. The company has assembled a seasoned executive team with extensive industry experience developing and commercializing specialty pharmaceutical products. Hyperion is headquartered in South San Francisco, CA. For additional information, visit: www.hyperiontx.com.
AMMONUL® is indicated as adjunctive therapy for the treatment of acute hyperammonemia and associated encephalopathy in patients with deficiencies in enzymes of the urea cycle. The most common adverse reactions are vomiting (9%), hypokalemia (7%), hyperglycemia (7%), convulsions (6%), and mental impairments (6%). Do not administer to patients with known hypersensitivity to sodium phenylacetate or sodium benzoate. Acute symptomatic hyperammonemia should be treated as life-threatening. Uncontrolled hyperammonemia can result in brain damage or death. Dialysis may be required, preferably hemodialysis, to remove a large burden of ammonia. Administration must be through a central line; use of a peripheral line may cause burns. Do not administer undiluted product. Because of prolonged plasma levels achieved by phenylacetate in pharmacokinetic studies, repeat loading doses should not be administered. Use caution when administering to patients with hepatic or renal insufficiency. AMMONUL® may cause nausea and vomiting. An antiemetic may be administered during infusion. See the prescribing information for a complete listing of warnings, precautions, and drug interactions.
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.
Hyperion Therapeutics, Inc.