Dynogen Presents Results of Its Positive Phase 2a IBS-c Study with DDP733

Results presented at Digestive Disease Week 2008
WALTHAM, Mass.--(Business Wire)--
Dynogen Pharmaceuticals, Inc. announced today the presentation of
positive results from its Phase 2a clinical trial for DDP733
(pumosetrag) as a treatment for irritable bowel syndrome with
constipation (IBS-c) at the Digestive Disease Week 2008 (DDW)
scientific meeting. The randomized, double-blind, placebo controlled,
parallel group study established clinical proof-of-concept and
demonstrated a statistically significant improvement over placebo in
the endpoint of overall subject global assessment (OSGA) of IBS. The
drug candidate was also well-tolerated. Dynogen previously reported
top-line results from this Phase 2a trial in February 2007. The DDW
abstract was co-authored by Dynogen and a team of investigators from
leading clinical centers in Canada.

DDP733 is an oral prokinetic drug which Dynogen is developing as a
treatment for both IBS-c and nocturnal gastroesophageal reflux disease
(NGERD). In the Phase 2a IBS-c study, 91 patients were randomized in a
double-blind fashion to one of five treatment groups (placebo, 0.2,
0.5, 0.8 or 1.4 mg) and study medication was administered three times
per day for 28 days. Patients used a diary to record their overall
global assessment of relief of IBS, as well as data related to
specific IBS symptoms, study medication, rescue medication use, and
adverse events. DDP733 achieved a statistically significant benefit in
the protocol defined clinical endpoint of overall relief of IBS as
measured by OSGA with 54% of subjects in the 1.4 mg dose group
responding to treatment compared to 15% of subjects in the placebo
group (p=0.039). No other treatment groups were statistically
different from placebo. Consistent improvements in the individually
recorded symptoms supported overall efficacy. A pharmacodynamic
assessment of gastrointestinal transit was included in the study, but
did not yield interpretable results. DDP733 was safe and
well-tolerated in this study.

"We believe the strong clinical efficacy and good safety profile
will clearly differentiate DDP733 from other drugs for IBS-c," said
Dr. Suhail Nurbhai, MRCP, Vice President of Clinical Development at
Dynogen. "DDP733 represents a valuable opportunity to provide a new
therapeutic option for a poorly served patient population, and
presenting these results at DDW underlines the potential of this
program."

"With limited treatment options available to those suffering from
IBS-c, there is a tremendous need for safe and efficacious
alternatives to address the debilitating symptoms that affect these
patients," said Dr. William Paterson, M.D., Chief of the Division of
Gastroenterology at Queen's University in Kingston, Ontario. "DDP733
is a first-in-class treatment for IBS-c, and these clinical data look
very promising. I look forward to seeing the results from future
studies with this compound."

About DDP733

DDP733 is an oral, minimally absorbed, partial agonist of the
5-HT(3) receptor. In addition to the IBS-c program, Dynogen announced
results from a Phase 1b translational medicine gastroesophageal reflux
study of DDP733 in June 2007. In that study, DDP733 achieved
statistical significance over placebo on the primary endpoint of
reduction in the number of reflux events. The drug was safe and
well-tolerated in both studies. Dynogen initiated a Phase 2b study of
DDP733 in IBS-c patients in November 2007.

About Irritable Bowel Syndrome (IBS)

IBS affects approximately 12% of the U.S. population, or 27
million individuals. IBS is a chronic disease characterized by
abdominal pain and discomfort associated with altered bowel habit. IBS
is associated with $1.6 billion in direct medical costs and $19.2 in
indirect costs in the U.S. each year. Patients with IBS make an
average of 5.5 visits to the physician each year compared to 1.9
visits annually for people without bowel symptoms. Additionally,
people with IBS incur healthcare costs nearly 50% higher than the
average American, and miss three times as many days of work.

About Digestive Disease Week

DDW is the largest international gathering of physicians,
researchers and academics in the fields of gastroenterology,
hepatology, endoscopy and gastrointestinal surgery. Jointly sponsored
by the American Association for the Study of Liver Diseases, the
American Gastroenterological Association (AGA) Institute, the American
Society for Gastrointestinal Endoscopy and the Society for Surgery of
the Alimentary Tract, DDW takes place May 17-22, 2008, at the San
Diego Convention Center, San Diego, CA. The meeting showcases
approximately 5,000 abstracts and hundreds of lectures on the latest
advances in GI research, medicine and technology. For more
information, visit www.ddw.org.

About Dynogen Pharmaceuticals, Inc.

Dynogen is a clinical-stage company developing a portfolio of
treatments for gastrointestinal and genitourinary disorders. The
Company is focused on large and untapped markets in disease areas that
severely impair a patient's quality of life, such as irritable bowel
syndrome, gastroesophageal reflux disease and overactive bladder. The
Company leverages its development expertise to identify promising
clinical compounds and rapidly advance them towards registration
www.dynogen.com.

Dynogen Pharmaceuticals, Inc.
Heather Savelle, 781-839-5149
hsavelle@dynogen.com
or
MacDougall Biomedical Communications
Christopher Erdman, 781-235-3060
cerdman@macbiocom.com

Copyright Business Wire 2008