FDA warns against Intercept’s liver disease drug after 19 deaths

After as many as 19 patients died of a liver-disease drug from Intercept Pharmaceuticals Inc, the US Food and Drug Administration on Thursday warned doctors about risks from the product that the company is seeking to make into a blockbuster.

The FDA warned that Intercept's drug Ocaliva was being incorrectly dosed in some patients with a rare liver disease, increasing the risk of liver injury and death.

Shares of the drugmaker sank 24.9 per cent to $73.70 at 4:00 pm Thursday in New York, the company's biggest loss since November 2014.

While the cause of the death wasn't available in most cases, seven of the patients who died were taking Ocaliva more frequently than is recommended, the agency said in a safety announcement.

The drug ''is being incorrectly dosed in some patients with moderate to severe decreases in liver function, resulting in an increased risk of serious liver injury and death,'' the FDA said in its warning.

But it also said that the medication may be associated with liver damage in some patients with mild disease receiving the correct dose.

Intercept declined to immediately comment, telling Bloomberg and Reuters by email that it was reviewing the FDA's statement.

The FDA warning comes two weeks after Intercept gave healthcare providers prescribing information for Ocaliva and flagged reports of liver failure and deaths.

Ocaliva, approved last May, is used to treat primary biliary cholangitis (PBC), a rare, chronic liver disease that causes bile ducts in the liver to become inflamed, damaged and destroyed.

Apart from the 19 deaths, 11 cases of serious liver injury were associated with the use of Ocaliva, the FDA said.

"FDA's narrative about the high number of deaths and worsening of PBC cases strikes us as particularly concerning, and could tilt the FDA more toward a black box warning," Leerink analyst Joseph Schwartz said in a report to clients.

A black box warning is the strictest warning by the FDA that appears on a prescription drug's label, calling attention to serious or life-threatening risks of a drug.

However, RBC Capital Markets analysts told Reuters the risks flagged by the FDA were already known and included on the drug's label. The affected patients represent under 5 per cent of the overall PBC population, limiting likely commercial impact to Intercept, they said.

About 15,000 prescriptions for Ocaliva have been written since it was introduced, according to data from Symphony Health Solutions compiled by Bloomberg Intelligence. The drug is Intercept's only commercial product and was approved in the US in May last year.

In the quarter ended 30 June, Intercept generated $30.4 million in worldwide sales from Ocaliva.

The deaths could lead to restrictions on how Ocaliva is prescribed and additional warnings on the drug's label, which doesn't currently list death as a risk. The company would face a potential major safety issue as it tries to expand the drug's use to millions of patients with other conditions.

Earlier this month, Intercept said it had reviewed 10 deaths of patients who had taken the drug. The company warned doctors that Ocaliva can cause injuries, organ failure, or death if it's not used exactly as intended in patients with primary biliary cholangitis, a relatively rare liver condition for which the drug was approved last year.

Rival treatments being tested at other drugmakers could threaten Ocaliva's market potential if they don't have the same risks, Bloomberg points out. Intercept is in the final stages of testing Ocaliva for nonalcoholic steatohepatitis, or NASH, which is associated with being overweight.

Three per cent to 12 per cent of Americans have NASH, according to the US National Institutes of Health, making it a huge potential market. According to Bloomberg, analysts have projected that the drug will become a blockbuster, with more than $1 billion in sales by 2021, though the disclosure of deaths may change that.