The U.S. Food and Drug Administration declined full approval for Intercept Pharmaceuticals' liver disease drug, raising questions about its future in the market.

The drug, Ocaliva, will continue to be available in the U.S. under the accelerated approval status, the company said.

Under the accelerated pathway, the FDA mandates additional trials that verify the drug's benefits. If the data from the trials do not show the drug's effectiveness, the regulator could ask the company to withdraw the drug from the market.

Ocaliva received the FDA's accelerated approval in 2016 to treat patients with primary biliary cholangitis, a rare disease that causes inflammation of small bile ducts in the liver and can eventually destroy them.

Recruitment to the drug's confirmatory trial was stopped early due to difficulties in enrolling rare disease patients. Less than 200,000 cases of primary biliary cholangitis are recorded in the U.S. every year, according to the American Liver Foundation.

Intercept said the health regulator will continue reviewing safety data for the drug.

The FDA's decision is in line with the recommendation made by a panel of independent experts in September, which said available data does not clearly prove the drug's effectiveness or remove doubts about its safety.

"I think the future of the drug is now largely up to the applicant and potential patients who would enroll in new trials," said Julia Wattacheril, MD, MPH, associate professor at Columbia University Vagelos College of Physicians and Surgeons, ahead of the decision.

Wattacheril added it was unclear if there was a desire to invest more resources in collecting further data for the drug.

Ocaliva and ursodeoxycholic acid were among the first few treatments for the disease to be approved in the U.S. Since then, several others, including Gilead's Livdelzi, have become available for patients.

In June, the European medicines regulator revoked Ocaliva's conditional authorization and said the benefits had not been confirmed.