BOSTON – Cilofexor, a nonsteroidal farnesoid X receptor (FXR) agonist, can improve disease biomarkers in patients with primary biliary cholangitis (PBC), based on results of a phase 2 trial.
Compared with placebo, patients treated with cilofexor had significant reductions in serum alkaline phosphatase (ALP), gamma-glutamyltransferase (GGT), C-reactive protein (CRP), and primary bile acids, reported lead author, of Swedish Medical Center in Seattle, and colleagues.
Dr. Kowdley, who presented findings at the annual meeting of the American Association for the Study of Liver Diseases, began by offering some context for the trial.
“There’s a strong rationale for FXR agonist therapy in PBC,” he said. “FXR is the key regulator of bile acid homeostasis, and FXR agonists have shown favorable effects on fibrosis, inflammatory activity, bile acid export and synthesis, as well as possibly effects on the microbiome and downstream in the gut.” He went on to explain that cilofexor may benefit patients with PBC, primary sclerosing cholangitis, or nonalcoholic steatohepatitis (NASH), noting preclinical data that have demonstrated reductions in bile acids, inflammation, fibrosis, and portal pressure.
The present trial involved 71 patients with PBC who lacked cirrhosis and had a serum ALP level that was at least 1.67 times greater than the upper limit of normal, and an elevated serum total bilirubin that was less than 2 times the upper limit of normal. Patients were randomized to receive either cilofexor 30 mg, cilofexor 100 mg, or placebo, once daily for 12 weeks. Stratification was based on use of ursodeoxycholic acid, which was stable for at least the preceding year. Safety and efficacy were evaluated, with the latter based on liver biochemistry, serum C4, bile acids, and serum fibrosis markers.
Across the entire population, baseline median serum bilirubin was 0.6 mg/dL and median serum ALP was 286 U/L. After 12 weeks, compared with placebo, patients treated with cilofexor, particularly those who received the 100-mg dose, showed significant improvements across multiple measures of liver health. Specifically, patients in the 100-mg group achieved median reductions in ALP (–13.8%; P = .005), GGT (–47.7%; P less than .001), CRP (–33.6%; P = .03), and primary bile acids (–30.5%; P = .008). These patients also exhibited trends toward reduced aspartate aminotransferase and aminoterminal propeptide of type III procollagen; Dr. Kowdley attributed the lack of statistical significance to insufficient population size.
Highlighting magnitude of ALP improvement, Dr. Kowdley noted that reductions in ALP greater than 25% were observed in 17% and 18% of patients in the 100-mg and 30-mg cilofexor groups, respectively, versus 0% of patients in the placebo group.
Although the 100-mg dose of cilofexor appeared more effective, the higher dose did come with some trade-offs in tolerability; grade 2 or 3 pruritus was more common in patients treated with the higher dose than in those who received the 30-mg dose (39% vs. 10%). As such, 7% of patients in the 100-mg group discontinued therapy because of the pruritus, compared with no patients in the 30-mg or placebo group.
Responding to a question from a conference attendee, Dr. Kowdley said that ALP reductions to below the 1.67-fold threshold were achieved by 9% and 14% of patients who received the 30-mg dose and 100-mg dose of cilofexor, respectively.
“We believe these data support further evaluation of cilofexor for the treatment of cholestatic liver disorders,” Dr. Kowdley concluded.
The study was funded by Gilead. The investigators disclosed additional relationships with Allergan, Novartis, GlaxoSmithKline, and others.
SOURCE: Kowdley KV et al. The Liver Meeting 2019.