XenoPort drops MS drug after poor trial results

USA-based XenoPort (Nasdaq: XNPT) saw its shares fall 12.7% to $5.89 in mid-morning trading on Monday (May 20), after it revealed top-line results from its pivotal Phase III clinical trial of arbaclofen placarbil (AP) for the treatment of patients with spasticity due to multiple sclerosis (MS), which failed to demonstrate demonstrating that AP provided statistically significant improvement relative to placebo in the co-primary endpoints of the study.

Ronald Barrett, chief executive of XenoPort, stated: “We are obviously disappointed that the co-primary efficacy endpoints were not met. Based on the results of the study, we have decided to terminate further investment in this program. We will be working diligently to shut down all activities related to AP development, and plan to provide an update in the future on the impact of these expected savings on our cash burn guidance. We remain committed to allocating our resources to build value through the focused commercialization of Horizant [gabapentin enacarbil, for Restless Legs Syndrome] and advancing the development of our novel fumarate product candidate, XP23829.”

Details of the Ph III study