We read with great interest the article by Hirschfield et al,1 who evaluated the efficacy and safety of obeticholic acid (OCA) in a randomized, controlled trial of patients with primary biliary cirrhosis (PBC) who had exhibited an inadequate response to ursodeoxycholic acid (UDCA) therapy. They concluded that daily doses of OCA, ranging from 10 to 50 mg, significantly reduced the serum concentrations of alkaline phosphatase (ALP), γ-glutamyl transpeptidase (γ-GT) and alanine aminotransferase in this population.