A randomized controlled trial involving 165 patients with primary biliary cirrhosis who had not responded to therapy with ursodeoxycholic acid has shown that adding obeticholic acid to the treatment regime, at a range of doses, is more effective than placebo. At the end of the study, patients who received obeticholic acid had reduced levels of alkaline phosphatase, γ-glutamyl transpeptidase and alanine aminotransferase compared with those given placebo. The incidence and severity of adverse events was lowest in patients given the lowest dose.