In a recent paper, published in the Journal of Hepatology, Kowdley, et al., reported a randomized, placebo-controlled, dose-finding study of Obeticholic acid (OCA), which has been approved for the therapy of Primary Biliary Cholangitis (PBC). OCA is a potent farnesoid X receptor (FXR) and the study included 76 patients with Primary Sclerosing Cholangitis (PSC) randomized to either placebo (n=25), OCA 1.5-3 mg (n=25), or OCA 5-10 mg (n=26). The primary endpoints of the study were improvement in serum alkaline phosphatase, a potential marker of disease severity, from baseline to week 24, and safety of OCA use. At week 24, serum alkaline phosphatase was significantly reduced with OCA 5-10 mg group vs. placebo group but not significantly reduced with OCA 1.5-3 mg group vs. placebo group. Of note, the overall reduction in serum alkaline phosphatase observed in this study was not lower than that observed with UDCA monotherapy among PSC patients in the past. The most common treatment-emergent adverse event was dose-related pruritus (placebo, 46%; OCA 1.5-3 mg, 60%; OCA 5-10 mg, 67%). No new safety signals were noted. A study limitation was an early termination (due to administrative reasons) of the long term safety extension (LTSE). Because the majority (93%) of the LTSE patients discontinued OCA before the month 24 visit, the number of patients evaluable for all liver biochemistry outcomes declined after month 12 and the results must be interpreted with caution. This is a promising study. Follow-up investigations are needed to validate these findings of OCA use for the future management of PSC patients.
Read the paper from Dr. Kowdley