XenoPort Announces Initiation Of A Phase 2b Clinical Trial Of Arbaclofen Placarbil In Patients With Gastroesophageal Reflux Disease

Main Category: Acid Reflux / GERD
Also Included In: Clinical Trials / Drug Trials
Article Date: 21 Oct 2009 - 1:00 PDT

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XenoPort, Inc. (Nasdaq:XNPT) announced today that it has initiated a Phase 2b clinical trial of arbaclofen placarbil (AP), also known as XP19986, in patients with gastroesophageal reflux disease (GERD) who remain symptomatic despite treatment with a proton pump inhibitor (PPI). The trial is a multi-center, randomized, double-blind, placebo-controlled study designed to assess the efficacy and safety of AP as adjunctive therapy to PPIs.

Ronald W. Barrett, Ph.D., XenoPort's chief executive officer, stated, "Based on the encouraging data in PPI-experienced patients from our previous monotherapy study and regulatory feedback regarding the path for approval of AP as adjunctive therapy, we are advancing our development program in GERD. Given its unique mechanism of action, we believe AP has the potential to provide symptomatic relief to GERD patients inadequately responding to PPIs."

XenoPort expects to enroll approximately 425 subjects in this trial, which is being conducted in the United States and Canada. Subjects with a history of incomplete response to a PPI will undergo a four-week run-in on PPI therapy followed by a six-week treatment period on PPI therapy plus either 20 mg or 40 mg of AP dosed once daily, 20 mg or 30 mg of AP dosed twice daily or placebo. The primary endpoint of the study will examine heartburn events. Regurgitation will be assessed as a key secondary endpoint.

About XP19986

AP (arbaclofen placarbil) is a Transported Prodrug of R-baclofen that is designed to engage natural nutrient transport mechanisms found on intestinal cell membranes, thereby gaining efficient entrance into the bloodstream. AP is then rapidly converted by high-capacity enzymes to R-baclofen and natural substances that have well-studied, favorable safety characteristics.

R-baclofen is an agonist of a target known as the gamma amino-butyric acid(B), or GABA(B), receptor. Racemic baclofen (a mixture of R and S isomers) has been approved for the treatment of spasticity and has been shown in clinical studies to have efficacy in a number of other therapeutic indications, including GERD.

About GERD

GERD is a digestive system disorder affecting approximately 20% of the U.S. population. Common symptoms include heartburn and regurgitation. Current treatment of GERD primarily involves suppression of acid secretion through the use of antacids, PPIs and H2 receptor antagonists. PPIs are the most efficacious and commonly used therapy to treat GERD. While PPIs improve symptoms in the majority of GERD patients, it is estimated that up to 40% of patients on once-daily PPI therapy continue to experience breakthrough symptoms.

Source
XenoPort