XenoPort is shelving one of its two development programs for arbaclofen placarbil after its Phase IIb heartburn study failed to demonstrate a clear benefit over a sugar pill. Researchers had been exploring the therapy's efficacy against gastroesophageal reflux disease in combination with proton pump inhibitors, but the company ($XNPT), which has been struggling to gain an approval for its lead therapy targeting restless leg syndrome, says none of the four doses used in the trial offered a statistically significant response.
"This was a binary event with only an estimated 50-60 percent chance of success, so it is a key setback for XenoPort," RBC Capital Markets analyst Michael Yee noted this morning.
"We are disappointed that AP failed to demonstrate clear efficacy over placebo in this trial," says CEO Ronald Barrett. "While we will continue to analyze the data, at this time, we do not believe the efficacy results of this study warrant our investment in further development for AP in GERD. We believe the AP safety profile observed in this study continues to support our planned Phase III development program for AP in patients with spasticity."
XenoPort shares--which were mauled last year after the FDA rejected its application for Horizant--slid another 12 percent this morning. The FDA is currently reviewing the NDA XenoPort and GlaxoSmithKline resubmitted for Horizant. They face a new PDUFA date of April 6. The biotech was forced to lay off half of its staff last year as it restructured in the wake of the regulatory snafu.
- see the XenoPort release