Dynogen Initiates Phase 1b Trial of DDP733 in Gastroesophageal Reflux Disease (GERD); New Approach for Treating Nighttime Heartburn.

WALTHAM, Mass. -- Dynogen Pharmaceuticals, Inc. announced today that dosing has begun for a double-blinded, placebo controlled Phase 1b trial designed specifically to examine DDP733 on the functional changes associated with gastroesophageal reflux. In addition to examining safety, the trial will be powered to yield important efficacy data to support the use of DDP733 as a treatment for nocturnal gastroesophageal reflux (NGERD). Dynogen is developing DDP733 for NGERD as an adjunctive treatment with current GERD therapies. DDP733 is also being studied by Dynogen for irritable bowel syndrome with constipation (IBS-c) in a Phase 2 clinical study.

DDP733 represents a new approach to treating NGERD as it directly impacts the reflux mechanisms of the digestive tract. Dynogen's preclinical studies have shown that DDP733 enhances the motility of the esophagus and tightens the lower esophageal sphincter between the esophagus and the stomach, thereby impeding the reflux of stomach contents into the esophagus and reducing the exposure of the lower esophagus to potentially harmful gastric contents.

"This is an exciting new approach to treating an intractable condition," said Dr. Suhail Nurbhai, MRCP, Vice President for Clinical Development. "Marketed therapies for GERD reduce the acidity of stomach contents, but do not resolve the underlying reflux problem. By addressing underlying motility abnormalities, including weak pressure of the sphincter between the stomach and esophagus, we expect DDP733 to prevent long term damage caused by continued reflux of stomach contents back into the esophagus. Our preclinical studies demonstrated that DDP733 induces a rapid and dose-dependent increase in the pressure of the lower esophageal sphincter and promotes clearance of secretions from the esophagus, reducing the time that the lower esophagus is exposed to acidity. The studies also found that DDP733 did not interfere with normal sphincter and esophageal function during swallowing, suggesting that DDP733 could be an effective treatment for patients not finding relief from existing acid suppressive therapies," Dr. Nurbhai added.

"With one-fifth of an estimated 20 million NGERD patients not responding to currently available therapies, we are developing an important treatment option for patients suffering from this disease," said Lee R. Brettman, M.D., Chief Executive Officer at Dynogen. "The initiation of this trial underscores our ability to rapidly generate value by building and advancing a clinical pipeline that addresses the growing need for new and better GI therapeutics."

About DDP733

DDP733 is an oral, serotonin type 3 receptor (5-HT3) partial agonist. Serotonin is a neurotransmitter that is known to be involved in the control of the gastrointestinal (GI) system. Preclinical studies of DDP733 established the compound's prokinetic properties (the ability to promote the motility of the GI tract) and demonstrated that DDP733 induces a rapid increase in the tightening of the sphincter between the stomach and the esophagus, halting the reflux of stomach contents back into the esophagus. Dynogen's preclinical studies have also shown that DDP733 is minimally absorbed by the cells lining the gastrointestinal tract and, as a result, more of the product candidate remains available at the desired local site of action. Clinical studies of the compound have demonstrated favorable safety and pharmacokinetic profiles.

Dynogen licensed preclinical, clinical and manufacturing data and patent rights to DDP733 from Mitsubishi Pharma Corporation in October 2004. In January 2006, Mitsubishi was awarded U.S. Patent 6,967,207 covering the use of DDP733 for the treatment of GERD, under which Dynogen has an exclusive license. In addition, Dynogen has filed patent applications of its own worldwide covering the use of DDP733 alone and in conjunction with acid reducing agents for the treatment of NGERD.

About Nocturnal Gastroesophageal Reflux Disease (NGERD)

Gastroesophageal reflux disease (GERD) is a chronic condition that afflicts over 30 percent of adults in the United States. Persistent heartburn is the most frequent symptom of GERD, but patients may also experience acid regurgitation into the esophagus, dyspepsia (stomach pain) and dysphagia (difficulty swallowing). GERD affects all age groups, although the incidence increases markedly after the age of 40. If left untreated, complications of GERD can include esophageal erosions or ulcers and abnormal narrowing of the esophagus. Years of chronic heartburn, left untreated, can lead to aggressive esophageal cancer, currently the fastest growing cancer in the United States. NGERD is the occurrence of GERD at night, typically while lying down to sleep. Symptoms associated with stomach reflux are exacerbated by the lack of assistance from gravity while lying recumbent. NGERD is commonly associated with a higher risk and a higher degree of esophagitis: acid remains in the esophagus for prolonged periods because there is less swallowing and less saliva produced to neutralize the acid. It is estimated that approximately one-third of patients suffering from GERD also suffer from NGERD.

About Dynogen Pharmaceuticals, Inc.

Dynogen is a clinical-stage company developing a portfolio of more effective treatments for gastrointestinal and genitourinary disorders. The Company is focused on capturing value in attractive 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. Dynogen currently has multiple double-blind, placebo-controlled Phase 2 studies underway. www.dynogen.com.