Bausch Health’s Rifaximin SSD Fails Phase III Hepatic Encephalopathy Trials

Bausch Health’s new rifaximin formulation, amorphous-rifaximin solid soluble dispersion (SSD), failed to meet primary endpoints in two Phase III trials (RED-C-3131 and RED-C-3132) for hepatic encephalopathy (HE) prevention. The placebo-controlled studies, involving over 1,000 adults with liver cirrhosis across 17 countries, aimed to delay the first onset of HE. Results showed no significant difference between rifaximin SSD and placebo.

Following the announcement, Bausch’s stock fell over 10%, from $6.57 to $5.91. The company has not disclosed whether key secondary endpoints, such as time to hospitalization or first overt HE episode, were met. CEO Thomas Appio stated that datasets will continue to be reviewed for further development opportunities.

HE is a severe complication of cirrhosis, affecting up to 40% of patients and characterized by cognitive impairment, confusion, and sleep disturbances. No approved preventive therapies currently exist. Meanwhile, alternative approaches, including fecal microbiota transplantation, mesenchymal stem cells, and GABA-A modulators, are under investigation globally.

31-01-2026