Salix Pharmaceuticals received FDA approval for Xifaxan 550 mg tablets to reduce the risk of overt hepatic encephalopathy (HE) recurrence in patients 18 years or older with advanced liver disease. HE is caused by chronic liver failure, resulting in cognitive, psychiatric, and motor impairments.
Salix anticipates that Xifaxan will be available for physicians and patients by the end of May 2010. The company hopes 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 orphan drug designation for use in HE and was previously approved for traveler’s diarrhea. Its approval was supported by findings from a randomized, double-blind, placebo-controlled, multinational trial of maintenance therapy in HE conducted in 299 subjects.
The study demonstrated a statistically significant and clinically meaningful reduction in the risk of overt HE recurrence. The primary endpoint—the risk of experiencing a breakthrough overt HE episode—was reduced by 58% among those treated with Xiflaxan 550 mg compared with placebo. The key secondary endpoint—risk of experiencing HE-related hospitalization—was reduced by 50%.
Xifaxan was not studied in patients with the most severe forms of liver disease. Since most patients were also taking lactulose, a synthetic sugar that helps prevent absorption of ammonia from the intestine, during the trial, the efficacy of Xifaxan as a stand-alone treatment for HE could not be assessed, the FDA reports. The most common adverse reactions associated with the use of Xifaxan in patients with liver disease include peripheral edemanausea, gas, and headache.