FDA Approves Madrigal Pharmaceuticals Drug as First Treatment for Common NASH Liver Disease

The Food and Drug Administration on Thursday approved the first-ever treatment for a common and potentially deadly form of liver disease that affects millions worldwide.

The FDA's decision means Madrigal Pharmaceuticals has succeeded in a disease area that several larger companies have failed — or are still trying to break into. Shares of the Madrigal jumped more than 20% in extended trading Thursday following the approval.

Novo Nordisk and Eli Lilly are testing their respective blockbuster weight loss injections as treatments for the same kind of liver disease, called non-alcoholic steatohepatitis, or NASH.

Madrigal's drug, which will be marketed as Rezdiffra, is specifically approved to treat patients with NASH who also have moderate-to-advanced liver scarring. The treatment must be used with diet and exercise, according to the FDA.

NASH is a serious form of liver disease characterized by excess fat buildup and inflammation in the liver and can lead to liver scarring, also known as fibrosis, along with liver failure and liver cancer. The condition is often associated with other health problems, such as high blood pressure, Type 2 diabetes and obesity.

Roughly 6 to 8 million people in the U.S. have NASH with moderate to advanced liver scarring, according to an estimate cited by the FDA.

Madrigal said in a statement that the drug will be available in April. The company also said it has set up an assistance program to help people who don't have insurance access Rezdiffra. Madrigal has not disclosed how much the treatment will be.

"Previously, patients with NASH who also have notable liver scarring did not have a medication that could directly address their liver damage," said Dr. Nikolay Nikolov, acting director of the FDA's Office of Immunology and Inflammation.

Madrigal's drug specifically received an "accelerated approval "from the FDA. That designation clears drugs faster if they fill an unmet medical need for serious conditions, and requires Madrigal to further study the treatment and verify its clinical benefits.

MadrigaL's medication works by activating a thyroid hormone receptor in the liver to help reduce fat accumulation. Patients take it by mouth each day.

In a late-stage study published last month, Rezdiffra helped resolve symptoms of NASH and improve liver scarring without making the condition worse. Notably, the rate of serious adverse events was comparable between the patient group that took the drug and another group that received a placebo.

The most common side effects related to treatment were diarrhea, nausea and vomiting. 

Some specialists have started calling NASH metabolic dysfunction-associated steatohepatitis, or MASH, to avoid potentially stigmatizing language.