Valeant Pharmaceuticals International reported positive results Tuesday from a Phase III trial of retigabine for patients with drug-resistant, or refractory epilepsy.

News of the findings caused Valeant's shares (NYSE:VRX) to rise in early morning trading to a high of $14.40, closing Tuesday at $13.25, up $1.62, or 14 percent.

In the study, known as RESTORE 1, retigabine demonstrated statistically significant results for primary efficacy endpoints important for regulatory review by the FDA and the European Medicines Evaluation Agency, the Aliso Viejo, Calif.-based company said. The study of 306 patients is one of two pivotal Phase III studies of retigabine that will support drug marketing applications to be filed in the U.S. and Europe before the end of the year, Valeant said.

The study results confirmed a previous study published in the journal Neurology in April 2007.

RESTORE 1 evaluated the highest dose of retigabine (1,200 mg daily), while RESTORE 2, the company's second pivotal Phase III clinical trial, looks at lower doses of the drug. Results from the second trial are expected during the second quarter.

If approved, retigabine would target an estimated 30 percent of epilepsy patients whose seizures are not adequately controlled with currently available epilepsy medications. Individuals with refractory epilepsy, who do not achieve remission on the drugs often are severely disabled by their condition and are at increased risk of sudden unexpected death. In addition, they may experience memory loss, lower levels of school performance, depression and impaired psychosocial skills, according to Valeant.

Retigabine is being studied as an adjunctive therapy that would be used in addition to other standard drugs for epilepsy. Laurie Little, vice president of investor relations at Valeant, told BioWorld Today the company is "hoping that retigabine will have better efficacy" than some of other products currently used by epilepsy patients who have not seen their condition improve.

Valeant plans to further discuss the study results during a conference call set for Feb. 14.

Comprehensive efficacy and safety results from RESTORE 1 are expected to be presented at upcoming scientific meetings in the U.S. and the European Union, the company said. During RESTORE 1, some 26.8 percent of patients in the retigabine arm and 8.6 percent of patients in the placebo arm withdrew due to adverse events. The most common side effects associated with retigabine in RESTORE 1 included dizziness, somnolence, fatigue, confusion, dysarthria, ataxia, blurred vision, tremors and nausea.

At the completion of the RESTORE trials, retigabine will have been studied in more than 1,750 subjects, including more than 1,350 patients with epilepsy. More than 350 of those patients will have taken retigabine for 12 or more months, including a few who have taken retigabine for six or more years.

Retigabine is a potassium channel opener, the first of its kind to reach late-stage clinical development, Valeant said. It is believed that by facilitating the opening of specific neuronal potassium channels, retigabine causes a hyperpolarizing shift in the potassium current and thereby reduces the excitability of neuronal cells, a key mechanism for reducing the potential for seizures, according to the company.