US FDA approves expanded use of Mirum's liver disease drug

Signage is seen outside of FDA headquarters in White Oak, Maryland

By Pratik Jain and Puyaan Singh

(Reuters) -The U.S Food and Drug Administration has approved the expanded use of Mirum Pharmaceuticals' oral drug to treat itching caused by a liver disorder in patients aged five years and older, the company said on Wednesday.

Mirum's shares rose 6.6% to $29.6 in extended trading.

The health regulator's approval for the drug, branded as Livmarli, allows it to be used for treating itching caused by progressive familial intrahepatic cholestasis (PFIC), a genetic disorder that causes progressive liver disease typically leading to liver failure.

Livmarli is already approved for treating itching caused by another type of rare genetic liver disorder known as Alagille Syndrome (ALGS).

"The drug will be launched with immediate availability for eligible patients in the United States with the same pricing as it is for the approved ALGS indication," Mirum Pharmaceuticals CEO Chris Peetz said ahead of the FDA decision.

Reimbursement for the treatment may not be available until a couple of quarters after the approval, Peetz added.

The FDA approval on Wednesday was based on data from a late-stage trial of 93 PFIC patients aged between 1 and 17 years, where the drug helped reduce the severity of itching.

Mirum said it has submitted an application to the FDA to expand the use of a higher concentration formulation of Livmarli in younger patients with PFIC.

The California-based drugmaker has been betting on its Livmarli franchise, seeking potential expansions into multiple liver disease indications.

Livmarli brought in $141.8 million in sales for the company in 2023.

H.C. Wainwright analyst Ed Arce estimates 2024 net sales of $11 million for the PFIC indication, with about 32 patients on the therapy by this year-end. Arce also expects the drug's annual wholesale acquisition cost to be about $458,600.

(Reporting by Puyaan Singh, Pratik Jain and Mariam Sunny in Bengaluru; Editing by Shounak Dasgupta)