Now that new hepatitis C virus (HCV) treatments can cure up to 90 percent of affected patients, U.S. pharmaceutical companies are on the hunt to eliminate a “new” type of hepatitis: non-alcoholic steatohepatitis (NASH), an end stage of fatty liver disease that  affects up to 5 percent of the U.S. population, Reuters reports. 

The push is not without good reason. Industry experts predict that NASH, an illness driven by America’s ongoing obesity and diabetes epidemics, will surpass HCV to become the leading cause of liver transplants by 2020. The eventual market for the complex disease (which occurs when fat accumulates in the liver, causing inflammation, cirrhosis and permanent scarring) is also estimated to reach between $20 billion and $35 billion over the next few years. And so far, there are no available treatments for the condition.

Currently, Pfizer says it has three early-stage drugs in its clinical trial roster that aim to block or reverse fat accumulation in the liver. Bristol-Myers also has confirmed it is looking for additional assets to enhance its existing NASH drugs. Meanwhile, other big drugmakers such as Novartis, Merck & Co, Allergan, and Johnson & Johnson have started ramping up licensing deals or options on future deals in the space, hoping to make big profits in curing the condition.

Many small companies developing fatty liver disease medications also appear to be making major headway in curing the condition. They include Intercept Pharmaceuticals, Galectin Therapeutics, Genfit, Enanta Pharmaceuticals and Durect Corp, all of which industry insiders say have a chance to be among the first to market.

This is a big change from just a few years ago, when Gilead Sciences appeared to be the only large U.S. pharmaceutical company addressing fatty liver disease. Last year, Phase II data from a Gilead-developed NASH drug appeared to help reverse liver fibrosis in as little as six months. However, experts say it will be at least two to five years before any of these new advancements make it into the hands of those suffering with the progressive liver disease.

Drugmakers are also taking a wide range of approaches to treat NASH, given the multiple health issues people with the condition have that are also thought to contribute to liver damage, such as heart disease and diabetes. There are drugs targeting inflammation to reduce fibrotic scarring, medications that aim to address lipid regulation in the liver and other treatments that simply aim to directly halt or reverse liver fibrosis. Some companies are also testing existing diabetes treatments to assess their ability to treat NASH in tandem.

Meanwhile, investors appear to be hungrily eyeing the hepatitis arena once again, placing bets on which company will be first to market by buying company stocks. Drugmakers also seem to be looking to improve their chances of success by buying out smaller companies to amass numerous experimental drugs for their NASH programs, knowing that most will probably fail.

Hepatitis researchers estimate that up to 15 million people are suffering from fatty liver disease in the United States alone, with estimates for the prevalence of NASH in nations with fatty diets ranging from 5 to 20 percent of the population. In addition to liver scarring, the progressive liver disease can lead to cirrhosis, liver cancer and liver failure. 

Click here to learn more about NASH and it’s precursor, non-alcoholic liver disease (NAFLD).