The U.S. Food and Drug Administration granted marketing approval for Viread for the treatment of chronic hepatitis B, Gilead Sciences Inc. said reported late Monday.

Foster City-based Gilead (NASDAQ:GILD) said Viread is a once-daily tablet that works by blocking HBV DNA polymerase, the enzyme that is necessary for the virus to replicate in liver cells.

Viread has been available in the United States as a treatment for HIV infection in adults since 2001.

Because chronic HBV infection can persist for years without causing any noticeable symptoms, many people are unaware they are infected and do not seek treatment, Gilead said, adding that the disease disproportionately affects Asian Americans.

The approval of Viread expands Gilead’s hepatic health franchise. The company’s first treatment for chronic hepatitis B, Hepsera, is currently the most widely prescribed oral agent for the disease in the United States. The company is also developing small-molecule compounds for the treatment of hepatitis C and a hepatoprotectant for multiple forms of hepatitis-related liver fibrosis, including nonalcoholic steatohepatitis.

Viread was approved for the treatment of chronic hepatitis B in the European Union, Turkey, Australia and New Zealand earlier this year, and a marketing application is currently pending in Canada.