Valeant Pharmaceuticals Selects Next-Generation Potassium-Channel Openers for Pre-Clinical Development

Valeant Pharmaceuticals International (NYSE:VRX) today announced that it has selected several pre-Investigational New Drug (IND) candidates for its next-generation potassium-channel opener program. These new compounds add to Valeant’s growing expertise with a novel and promising new class of anti-epileptic drugs. Valeant is currently conducting two pivotal Phase 3 studies for retigabine, a neuronal potassium-channel opener as an adjunctive treatment for partial-onset seizures in patients with refractory epilepsy. Potassium-channel openers are a clinically validated target for epilepsy and show potential in treating other neurological conditions such as neuropathic pain. The newly selected candidates, similar in molecular structure to retigabine, have demonstrated much greater potency and potential efficacy in pre-clinical models, including a model of pharmacoresistant epilepsy. The compounds have demonstrated potency at levels that are 10 to 50 times higher than retigabine in opening the potassium-channel and at inhibiting seizure activity in animal models. In addition, the compounds demonstrated favorable pharmacokinetic and metabolic profiles. The candidates could represent a significant enhancement to the retigabine profile and therefore provide the potential for a sustainable potassium-channel franchise. "We are enthusiastic about the progress we are making to advance these promising next-generation potassium-channel openers,” said Wesley P. Wheeler, president, North America and Research and Development. "Our expanded understanding of neuronal potassium-channel openers, coupled with our development experience with retigabine and other neurology products, will allow us to develop this exciting new class of drugs for the market.” Following the completion of enabling studies, Valeant plans to submit an IND application to the United States Food and Drug Administration (FDA) in early 2008. 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). Enrollment into RESTORE 1 is nearly complete and enrollment into RESTORE 2 is expected to complete in the third quarter. At the completion of these trials and the open-label extension studies offered to all patients following completion of their participation in the RESTORE studies, retigabine will have been studied in more than 1,300 patients with epilepsy, more than 300 of whom will have taken the investigational product for a minimum of 12 months. Retigabine has not been found by the 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. FORWARD-LOOKING STATEMENTS This press release contains forward-looking statements, including, but not limited to, statements regarding the company’s plans to submit an IND application for the new potassium-channel opener compounds to the FDA in early 2008 and the potential of such compounds to address epilepsy and other neurological disorders, and the completion of RESTORE 1 and RESTORE 2 clinical trials. These statements are based upon the current expectations and beliefs of management and are subject to certain risks and uncertainties that could cause actual results to differ materially from those described in the forward-looking statements. These risks and uncertainties include, but are not limited to, risks and uncertainties related to the completion of the company’s clinical trials on retigabine and its ability to successfully advance new potassium-channel opener compounds through clinical development, including the validity of pre-clinical models and pharmacokinetic studies in predicting efficacy in treatment of diseases in humans, and market launch and other risks and uncertainties discussed in the company’s filings with the SEC. Valeant wishes to caution the reader that these factors are among the factors that could cause actual results to differ materially from the expectations described in the forward-looking statements. Valeant also cautions the reader that undue reliance should not be placed on any of the forward-looking statements, which speak only as of the date of this release. The company undertakes no obligation to update any of these forward-looking statements to reflect events or circumstances after the date of this release or to reflect actual outcomes.