FDA accepts for filing Salix Pharmaceuticals' NDA for rifaximin tablets

Salix Pharmaceuticals, Ltd. (NASDAQ:SLXP) today announced the Food and Drug Administration (FDA) has accepted for filing and designated for Priority Review the Company’s New Drug Application (NDA) for rifaximin tablets 550 mg for the maintenance of remission of hepatic encephalopathy (HE). Additionally, the FDA has informed the Company of its plan to schedule an Advisory Committee meeting in late February 2010 to discuss the application.

A Priority Review classification is granted to drugs offering major advances in treatment, or providing a treatment where no adequate therapy exists. Based on this classification, the FDA has issued an action date of December 24, 2009 under the Prescription Drug User Fee Act (PDUFA). However, the convening of an Advisory Committee in late February 2010 signals the December 24, 2009 action date will be delayed.

“We are pleased with the FDA’s acceptance for filing of the rifaximin NDA and their decision to grant Priority Review for our application,” stated Bill Forbes, Pharm.D., Senior Vice President and Chief Development Officer, Salix Pharmaceuticals. “This review classification signals that the FDA considers that rifaximin has the potential to provide a significant advance in the treatment of hepatic encephalopathy. We are not surprised at the FDA’s decision to convene an Advisory Committee to gain an independent recommendation from outside experts regarding rifaximin due to the fact that, if approved, rifaximin will be the first new option approved for the management of HE in over 30 years. We believe the availability of rifaximin has the potential to change the treatment paradigm for HE. Today’s news marks a milestone for Salix, rifaximin and patients suffering from this serious condition.”

Currently Salix estimates the U.S. commercial opportunity represented by the HE market is approximately $600 million. Hepatic encephalopathy occurs frequently in patients with cirrhosis as a result of their end-stage liver disease. Typically the cirrhosis is caused by a number of factors, such as alcohol and/or drug abuse, chronic viral hepatitis and autoimmune disease. Cirrhosis is a leading cause of death in the United States.¹ The number of cases of liver disease in the United States and around the world is rapidly increasing, with more than 7 million people in the United States being diagnosed with chronic liver disease.² There are reported to be more than 100,000 patients in the United States with overt HE.³

Rifaximin has been granted Orphan Drug designation by the FDA for use in hepatic encephalopathy. Salix believes this designation will provide seven years of marketing exclusivity in the United States if rifaximin gains approval from the FDA for HE.