Auspex Pharmaceuticals Announces Positive Results from Clinical Study of SD-254,...

Auspex Pharmaceuticals Announces Positive Results from Clinical Study of SD-254, A Next-Generation Potential Treatment for Depression

Deuterium-Substituted Version of Venlafaxine Exhibits Improved
Pharmacokinetic Profile
VISTA, Calif.--(Business Wire)--
Auspex Pharmaceuticals, a developer of next-generation medicines
with improved safety and performance through the targeted deuteration
of clinically validated drugs, today announced positive results from
its Phase 1 clinical trial evaluating SD-254, a Selective
Serotinin-Norepinephrine Reuptake Inhibitor (SNRI). Auspex is
developing SD-254, a deuterium-substituted version of venlafaxine, for
the treatment of Major Depressive Disorder.

In the clinical study conducted in 16 healthy volunteers, SD-254
exhibited a pharmacokinetic profile that appears to be superior to
that of venlafaxine and consistent with that required for increasing
safety and reducing side effects relative to existing therapies, while
maintaining high patient response rates. The company is planning
additional studies to build on these observations and support an
overall development plan for demonstrating safety and efficacy.

"These results represent the first validation in humans of
targeted deuterium substitution as a strategy for improving the
pharmacokinetics and thus potentially the safety and performance of
drugs," said founding scientist and Chief Scientific Officer, Dr.
Thomas G. Gant. "SD-254 has passed the first hurdle towards
demonstrating the desired pharmaceutical profile, and we look forward
to advancing its development."

"With the achievement of this important clinical milestone, Auspex
has successfully demonstrated the power of the drug deuteration
concept for the first time in man," said Dr. Pratik Shah, Executive
Chairman. "Depending on the drug class, this approach can potentially
lead to a variety of beneficial effects, including longer duration of
action, improved safety profile, reduced levels of toxic metabolites
and reduced inter-patient variability. The success we have announced
today demonstrates Auspex's ability to build on its strong
intellectual property position across multiple therapeutic areas and
to continue to generate drug candidates that address significant
market opportunities."

The deuteration approach also allows preservation or augmentation
of known, desired pharmacology. SD-254, for example, has intrinsic
pharmacology and physicochemical characteristics that are virtually
indistinguishable from venlafaxine, yet the metabolic profile is
postulated to produce a drug that may reduce known side effects.

About Auspex Pharmaceuticals

Auspex Pharmaceuticals, founded in 2001, is a developer of
next-generation medicines with improved safety and performance and a
pioneer in the targeted application of deuterium chemistry to
clinically validated drugs. Deuterium is a naturally occurring, safe
and stable isotope of hydrogen. The human body contains on average
over one gram of deuterium and individuals consume several grams of
deuterium annually through their diet. For many years the company has
worked to apply its targeted deuteration strategy to drug molecules
across multiple therapeutic areas. Concurrently, Auspex has secured a
proprietary position on several hundred compounds and has initiated
development of multiple clinical candidates. The goal of the company's
targeted deuteration strategy is to impart greater safety over
existing agents, while maintaining or improving efficacy through the
judicious use of deuterium as a replacement for metabolically labile
hydrogen atoms. The Auspex approach can rapidly generate potential
best-in-class therapeutics for significant markets, while reducing the
time, cost and risk of drug development. For more information on
Auspex Pharmaceuticals, please visit the company's website at
www.auspexpharma.com.

Auspex Pharmaceuticals
Valerie MacNeil, 760-599-1800
vmacneil@auspexpharma.com
or
Kureczka/Martin Associates
Joan Kureczka, 415-821-2413
Jkureczka@comcast.net

Copyright Business Wire 2008