Valeant Pharmaceuticals to Initiate Study of Retigabine for Pain Associated with Post-Herpetic Neuralgia.

ALISO VIEJO, Calif. -- Valeant Pharmaceuticals International (NYSE:VRX) announced today that it will initiate a clinical trial with retigabine in the treatment of pain associated with post-herpetic neuralgia (PHN). Valeant filed an Investigational New Drug (IND) application with the U.S. Food and Drug Administration (FDA) and following FDA review, the company will move forward with the clinical study. Retigabine is a first-in-class neuronal potassium channel opener currently in Phase 3 development as an adjunctive treatment for partial-onset seizures in patients with refractory epilepsy.

"The initiation of the study is an important milestone in our development of retigabine and our studies of the drug in the treatment of pain," said Timothy C. Tyson, president and chief executive officer. "PHN can be a highly debilitating condition affecting approximately 20 percent of the nearly one million patients diagnosed with herpes zoster each year in the United States. Valeant is committed to providing innovative treatments worldwide for patients affected by disease and the physicians who treat them."

The clinical protocol titled, "A randomized, placebo-controlled, phase IIa proof-of-concept study to evaluate the efficacy of maximally tolerated doses of retigabine vs. placebo in reducing the pain associated with post-herpetic neuralgia" has been reviewed by the FDA. Its primary objective is to compare the average pain intensity during four weeks of maintenance therapy with maximally tolerated doses of retigabine vs. placebo in patients with PHN. A total of 180 subjects are planned to be enrolled and randomized to receive retigabine or placebo.

"We are pleased to initiate clinical studies on retigabine in the treatment of PHN to determine whether retigabine could represent a valuable new treatment option for patients with PHN, and warrant future investigation into the treatment of other neuropathic pain syndromes," said Wesley P. Wheeler, president, North America and Research and Development. "Retigabine has a novel mechanism of action unlike other pain treatments on the market. In vivo pharmacological studies show that retigabine alleviates behaviors associated with neuropathic and chronic pains in animal models, thus meriting its further investigation in these conditions."

About PHN

Post-herpetic neuralgia is a painful complication of herpes zoster and occurs when nerve fibers are damaged during an outbreak of herpes zoster, causing chronic and often excruciating pain that may continue for months or years. Currently available treatments for PHN include topical medications, over-the-counter analgesics, tricyclic antidepressants and anticonvulsants.

About Retigabine

Retigabine, an investigational compound, is currently being investigated in the Retigabine Efficacy and Safety Trials for Partial Onset Epilepsy (RESTORE), two large, pivotal Phase 3 trials that will evaluate the safety and efficacy of retigabine in refractory patients who are receiving one, two or three antiepileptic drugs (AEDs). To date, RESTORE 1 is 93 percent enrolled and RESTORE 2 is 72 percent enrolled. At the completion of these trials, retigabine will have been studied in more than 1,300 patients, more than 300 of which have taken the investigational product for a minimum of 12 months.

Retigabine has not been found by the Food and Drug Administration (FDA) or any other regulatory agency to be safe or effective in the diagnosis, mitigation, treatment or cure of any disease or illness. It may not be sold or promoted in the United States unless and until the FDA has approved a New Drug Application. Similar restrictions apply in other countries.

The most common side effects associated with retigabine to date include somnolence, dizziness, confusion, speech disorder, vertigo, tremor, amnesia, abnormal thinking, abnormal gait, paresthesia, diplopia, incoordination, nervousness, abnormal vision, asthenia, headache, nausea and diarrhea.

About Valeant

Valeant Pharmaceuticals International (NYSE:VRX) is a global specialty pharmaceutical company that develops, manufactures and markets a broad range of pharmaceutical products primarily in the areas of neurology, infectious disease and dermatology. More information about Valeant can be found at www.valeant.com.