Hyperion Therapeutics Completes Enrollment in Phase 1/2 Clinical Trial in Patients...

Hyperion Therapeutics Completes Enrollment in Phase 1/2 Clinical Trial in
Patients With Urea Cycle Disorders

SOUTH SAN FRANCISCO, Calif., July 22 /PRNewswire/ -- 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(R)
(sodium phenylbutyrate) in patients with urea cycle disorders (UCD). The
company plans to announce top-line results in the fourth quarter of this year.
(Logo: http://www.newscom.com/cgi-bin/prnh/20070905/AQW076LOGO)
"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.
About HPN-100
HPN-100 is a pro-drug of phenylbutryrate and a pre-pro-drug of
phenylacetic acid (PAA), the active moiety of BUPHENYL(R), 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.
About BUPHENYL(R)
BUPHENYL(R) 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(R) 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(R) 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: http://www.hyperiontx.com.
BUPHENYL is a registered trademark of Ucyclyd Pharma, Inc.
Full Prescribing Information for BUPHENYL(R) is available at
http://www.Buphenyl.com or by contacting Ucyclyd Pharma, Inc.
SOURCE Hyperion Therapeutics, Inc.

Christine Nash of Hyperion Therapeutics, Inc., +1-650-745-7844