FLINT trial halted early because of positive results

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FLINT trial may spark new therapies for NASH

Current data suggest that nonalcoholic fatty liver disease (NAFLD) is present in 30%-40% of adults in the United States, with a subset of this population having a more aggressive form of fatty liver called nonalcoholic steatohepatitis (NASH), which may progress to cirrhosis. NASH is currently the third-leading cause for liver transplantation and is predicted to become the most common within 10-15 years (Gastroenterology 2011;141:1249-53).

Most NAFLD patients are overweight or obese and have underlying insulin resistance or diabetes mellitus. Comorbid illness is also common, with cardiovascular disease being the leading cause of death (Clin. Gastroenterol. Hepatol. 2012;10:837-58). Treatment for this condition is predicated on losing weight via diet and exercise, with 7%-10% weight loss being associated with improvement in underlying liver disease. Unfortunately, it is quite difficult for most patients to lose and maintain this weight level, so attention has turned to pharmacotherapy as a possible adjunct to diet and exercise. To date, pioglitazone and vitamin E have shown the most promise but are not universally effective, and they are linked to unwanted side effects or potential disease associations (Clin. Gastroenterol. Hepatol. 2012;10:837-58).

Dr. Stephen A. Harrison
Obeticholic acid (OCA), a 6-alpha-ethyl derivative of chenodeoxycholic acid, was shown in an early phase II clinical trial of NAFLD patients with type 2 diabetes to improve insulin resistance (Gastroenterology 2013;145:574-82). Recently, an interim analysis from a phase IIb, 72-week, placebo-controlled trial of 25-mg OCA was reported that showed the study met its primary endpoint of a two-point improvement in the NAFLD activity score (NAS) without worsening fibrosis. However, total cholesterol and LDL levels were raised while HDL levels were lowered in this trial.

While these data are provocative, caution is needed until more complete data are presented. While the study met its primary endpoint, the report did not detail the source of the two-point improvement. NAS is based on an eight-point scale, with three points possible for the degree of steatosis, three points for lobular inflammation, and two points for ballooning degeneration of hepatocytes. Improvement in steatosis alone does not necessarily constitute improvement in NASH, the subset of disease that may progress in severity. It is important to know what percentage of patients actually resolved NASH or improved lobular inflammation or ballooning degeneration over placebo. Given that NASH patients are at increased risk for cardiovascular disease, it is concerning that serum cholesterol levels worsened. Details on LDL particle size and concentration as well as HDL subfractions are needed.

Additionally, further information on the tolerability and safety of OCA among NASH patients is eagerly awaited. While these preliminary data are promising, more details are needed before we can fully embrace this drug to treat NASH.

Dr. Stephen A. Harrison, COL, USA, MC, is director of medical education and associate dean, San Antonio Uniformed Services Health Education Consortium; chief of hepatology, Brooke Army Medical Center, San Antonio; professor of medicine, Uniformed Services University of the Health Sciences; and GI Consultant to the Office of the Surgeon General. He is an adviser to Genentech, Merck, and Nimbus Discovery, and has been on the speakers bureaus for Merck and Vertex within the past 12 months.



The phase II clinical trial of first-in-class farnesoid X receptor agonist obeticholic acid as a treatment for nonalcoholic steatohepatitis was stopped early because the trial endpoint was met with high significance, Intercept Pharmaceuticals announced Jan. 9.

The National Institute of Diabetes and Digestive and Kidney Diseases, which sponsored and conducted the FLINT trial, said in its statement that "OCA [obeticholic acid] has a significant beneficial effect on the liver damage due to NASH."

An interim analysis conducted by the Data Safety Monitoring Board of the trial found a highly statistically significant improvement in the primary endpoint, defined as "a decrease in the NAFLD Activity Score of at least two points with no worsening of fibrosis, as compared to placebo," the company said in a statement. The predetermined significance threshold for ending the trial was P less than .0031, but early results exceeded expectations with a significance of P = .0024.

An estimated 6 million adults in the United States have advanced liver fibrosis or cirrhosis caused bynonalcoholic steatohepatitis (NASH), said Dr. Mark Pruzanski, CEO of Intercept.

"This disease has seemingly come out of nowhere and has become an epidemic," he said. "On its current trajectory, NASH is expected to be the No. 1 indication for liver transplant over the next decade."

The FLINT trial, sponsored and conducted by the National Institute of Diabetes and Digestive and Kidney Diseases, studied the efficacy of a 25-mg. oral dose of obeticholic acid (OCA) in approximately half of 283 biopsy-confirmed NASH patients over a period of 72 weeks. Patients were randomized to receive either a 25-mg dose of OCA or placebo for the treatment period.

Participants were 18 years of age or older, with histologic evidence of nonalcoholic steatohepatitis, based on a liver biopsy, obtained no more than 90 days prior to randomization and a NAFLD activity score of 4 or greater with at least one in each component of the NAFLD activity score (steatosis scored 0-3; ballooning degeneration scored 0-2; and lobular inflammation scored 0-3). End of study biopsies were conducted in patients after the 72-week treatment period.

As specified in the protocol, a 24-week follow-up period will start, and all FLINT participants will stop taking the drug or placebo no later than Jan. 20.

Lipid derangements involving elevated total [cholesterol] and LDL cholesterol and reduced HDL cholesterol have been seen in OCA, compared with placebo-treated patients. While lipid abnormalities are not uncommon in NASH, researchers will be checking to see if lipids return to pretreatment levels during this 24-week follow-up period.

During this period, both FLINT investigators and trial participants will remain blinded to treatment. The NIDDK expects to present the results of the trial in the fourth quarter of 2014.

OCA has not only been studied as a promising treatment for NASH. A 2013 study also found that OCA increased insulin sensitivity and reduced markers of liver inflammation and fibrosis in patients with type 2 diabetes and nonalcoholic fatty liver disease. Additionally, OCA is currently in a phase III trial for the treatment of primary biliary cirrhosis.

A concurrent trial to study OCA as a treatment for NASH is underway in Japan, added Dr. Pruzanski, with top-line results expected in 2015. Dr. Pruzanski said he hopes the trial’s unexpected success will help pave the path to FDA approval, pending final NIDDK analyses and publication of the results.

The FLINT trial was sponsored and conducted by the National Institute of Diabetes and Digestive and Kidney Diseases.

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