Gilead Sciences (GILD -2.70%) has received FDA priority review status for its New Drug Application for sofosbuvir, the company announced Friday.

Sofosbuvir is a once-daily oral nucleotide analogue inhibitor for the treatment of chronic hepatitis C virus (HCV) infection. Nucleotide analogue inhibitors are antiviral drugs that bind to reverse transcriptase, preventing RNA conversion to DNA.

Hepatitus C is a closely related family of viral liver diseases composed of several subtypes (genotypes). According to the Centers for Disease Control, most patients infected with HCV develop chronic infections. Most of these develop some degree of chronic liver disease. Fewer than 20% of people with chronic HCV will develop cirrhosis of the liver. Fewer than 5% will end up dying of cirrhosis or liver cancer caused by the virus.

The FDA grants priority review status to drug candidates that may offer major advancements in treatment over existing options. The FDA has set a target review date of Dec. 8 under the Prescription Drug User Fee Act.

Gilead proposes the use of sofosbuvir and ribavirin, or RBV, as an all-oral therapy for genotype 2 and 3 HCV infection, and the use of sofosbuvir with RBV and pegylated interferon for patients who have never been treated for genotype 1, 4, 5, or 6 infections in the past.