Hepatic encephalopathy drug XIFAXAN 550 mg tablets receives FDA marketing approval

Salix Pharmaceuticals, Ltd. (NASDAQ:SLXP) today announced the U.S. Food and Drug Administration (FDA) has granted marketing approval for XIFAXAN^® (rifaximin) 550 mg tablets for reduction in risk of overt hepatic encephalopathy (HE) recurrence in patients 18 years of age or older. HE is a serious disorder caused by chronic liver failure, resulting in cognitive, psychiatric and motor impairments. This approval was supported by findings from the largest randomized trial of maintenance therapy in HE conducted to date, which assessed the efficacy and safety of XIFAXAN 550 mg tablets and demonstrated a statistically significant and clinically meaningful reduction in the risk of overt HE recurrence. The labeling for XIFAXAN 550 mg tablets includes data on both the risk reduction of overt HE recurrence as well as risk reduction of HE-related hospitalization.

“HE is a growing health issue among adults suffering from liver disease in the U.S. The imminent availability of XIFAXAN 550 mg tablets signals an important advancement for overt HE patients, their caregivers and the health care community supporting these patients”

HE occurs frequently in patients with cirrhosis as a result of end-stage liver disease. Typically, cirrhosis is caused by a number of factors, such as alcohol and/or drug abuse, chronic viral hepatitis and autoimmune disease. Currently, there are more than 600,000 cases of cirrhosis in the United States. Cirrhosis is the third most common cause of death, after heart disease and cancer, in people 45-65 years of age in the United States. An estimated 25,000 people die of cirrhosis each year in the United States. The number of cases of liver disease worldwide is rapidly increasing, with the prevalence of chronic liver disease in the United States estimated to be between six and seven million cases.^{iii, iv} There are reported to be approximately 200,000 patients in the United States who suffer from episodic overt HE. ^v,vi,vii

“HE is a growing health issue among adults suffering from liver disease in the U.S. The imminent availability of XIFAXAN 550 mg tablets signals an important advancement for overt HE patients, their caregivers and the health care community supporting these patients," said Bill Forbes, Pharm.D., Executive Vice President of Research and Development and Chief Development Officer, Salix Pharmaceuticals. “An episode of overt HE can result in a patient losing cognitive function or even death. These symptoms, in a number of incidences, necessitate a clinic or emergency room visit or hospital admission. We are pleased to bring XIFAXAN 550 mg tablets to market and believe the utilization of this treatment should serve to reduce the recurrence of overt HE as well as the number of hospitalizations associated with this serious condition.”

Salix anticipates XIFAXAN 550 mg tablets to be available for physicians and patients by the end of May 2010. In preparation for the launch, the Company is targeting to begin shipping product to wholesalers in early May and to complete the training of its 160-member sales force during the week of May 17.

XIFAXAN has been granted Orphan Drug designation by the FDA for use in hepatic encephalopathy. With XIFAXAN 550 mg tablets now approved by the FDA, Salix believes this designation should provide seven years of marketing exclusivity in the United States.

FDA approval of XIFAXAN 550 mg tablets was based on a 299 subject, double-blind, placebo-controlled, multinational, Phase 3 clinical trial, the largest randomized trial of maintenance therapy in HE conducted to date. Trial results demonstrated a statistically significant and clinically meaningful reduction in the risk of overt HE recurrence.^viii The primary endpoint – the risk of experiencing a breakthrough overt HE episode – was reduced by 58 percent in XIFAXAN 550 mg-treated subjects compared with placebo (p<0.0001). The key secondary endpoint – risk of experiencing HE-related hospitalization – was reduced by 50 percent in XIFAXAN 550 mg-treated subjects compared with placebo.