TRENTON, N.J. – Patients with hepatitis C have yet another advanced treatment option, as the Food and Drug Administration on Thursday approved a new once-a-day pill developed by drugmaker Merck. The FDA said Merck can begin marketing Zepatier for patients with two of the subtypes the liver-destroying virus, types 1 and 4. The combination pill includes the medications elbasvir and grazoprevir, which attack the virus in two different ways. Merck & Co. said the price will be $54,600 for a 12-week treatment regimen. Insurers will likely still demand some discounts on that price.

The approval is good news for patients, because the growing competition should crimp the sky-high prices for hepatitis C drugs, and the additional option means there’s one that will work for nearly every subgroup of people with hepatitis C.

Roughly 3 million Americans and millions more in other countries have the blood-borne virus, which doesn’t produce symptoms – jaundice, fluid accumulation in the abdomen, bleeding and infections – until significant damage has been done. Many develop liver cancer or cirrhosis and require a liver transplant, but die before a match is available.

There are six genetic subtypes of the hepatitis C virus, and the five drugs now approved in the U.S. generally only treat some of those. Patients with both hepatitis C and HIV or another serious condition are particularly difficult to treat, as are those who already have severe liver or kidney damage.