May 4, 2009
Salix reported positive results from a phase III trial of rifaximin for the treatment of hepatic encephalopathy (HE). This multinational, randomized, double-blind, placebo-controlled trial enrolled 299 subjects who received either rifaximin 550 mg twice daily or placebo. It was designed to assess the long-term (six months) efficacy, safety and tolerability of rifaximin in maintaining remission compared to placebo. The primary endpoint was time to first breakthrough HE episode. Rifaximin significantly reduced the risk of an HE breakthrough episode by 58% compared to placebo (p<0.0001). At six months, breakthrough HE episodes were experienced by 22% in the rifaximin group and 46% in the placebo group (p<0.0001). This reduction of the risk of HE breakthrough was maintained across all subgroups in the study, indicating a high degree of consistency in the intent-to-treat population. In addition, rifaximin, had a safety profile that was comparable to placebo after six months of treatment.