XenoPort Sinks as Spasticity Drug For MS Fails in Trial

XenoPort Inc., the maker of the drug Horizant for Restless Legs Syndrome, sank the most in almost three years after an experimental medicine failed to meet goals of a late-stage clinical trial.

XenoPort dropped 15 percent to $5.72 at the close in New York, the biggest single-day decline since July 2010. The shares of the Santa Clara, California-based company have declined 26 percent this year.

XenoPort is stopping development of arbaclofen placarbil, an experimental treatment for spasticity in multiple sclerosis patients, after the therapy didn’t help more than placebo, the company said in a statement today. Brian Abrahams, an analyst with Wells Fargo, had estimated sales of $77 million by 2017 for the drug.

“This is disappointing, given promising phase 2 data,” Abrahams wrote in a research note today. “The failure does remove a potential floor in valuation.”

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