XenoPort Initiates Phase 2b Trial For Arbaclofen Placarbil

XenoPort 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).

Reportedly, the trial is a multi-center, randomised, double-blind, placebo-controlled study designed to assess the efficacy and safety of AP as adjunctive therapy to PPIs. The primary endpoint of the study will examine heartburn events. Regurgitation will be assessed as a key secondary endpoint.

The company expects to enroll approximately 425 subjects in the trial, which is being conducted in the US and Canada. Subjects with a history of incomplete response to a PPI are expected to undergo a four-week run-in on PPI therapy followed by a six-week treatment period on PPI therapy plus either 20 mg or 40mg of AP dosed once daily, 20mg or 30mg of AP dosed twice daily or placebo.

Ronald Barrett, CEO at XenoPort, said: “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.”