Sept 11 (Reuters) -

Staff reviewers at the U.S. Food and Drug Administration said on Wednesday a

confirmatory trial did not show the effectiveness of Intercept's liver disease

drug, which received the health regulator's accelerated nod in 2016.

Under the accelerated pathway, companies are required to conduct

additional trials to establish their drug's benefits. Failure to do so can

sometimes lead to market withdrawal.

Intercept's oral drug, Ocaliva, had been approved under the accelerated

approval pathway to treat patients with primary biliary cholangitis (PBC), a

rare disease that causes inflammation of small bile ducts in the liver and can

eventually destroy them.

In 2021, FDA restricted use of Ocaliva to PBC patients who did not have

advanced cirrhosis or severe scarring of the liver.

The FDA had said some patients with advanced cirrhosis who received

Ocaliva developed liver failure.

The staff advisers said on Wednesday Ocaliva's confirmatory trial did

not show the drug was effective in PBC patients with or without advanced

scarring.

They also raised concerns about the drug's safety, as 11 patients who

received it during the trial died or required a liver transplant, compared with

two patients on placebo.

The concerns come ahead of a meeting of independent experts on Friday,

where panelists will vote on whether the drug's benefits outweigh its risks.

Intercept said only one case of liver transplant was possibly related to

the drug.

The company, which holds the drug's U.S. commercial rights, was acquired

by Italy's Alfasigma for nearly $800 million last year. Intercept had reported

sales of $152 million for the first half of 2023.

The FDA last month granted accelerated approval to Gilead's

drug for treating PBC, Livdelzi.

Accelerated approvals allow FDA to move drugs for life-threatening

conditions to the market more quickly, but they have

been criticized

because some drugs are later proven to be ineffective.