The US Food and Drug Administration has given Foster City, California–based Gilead the go-ahead to market Harvoni, the first fixed-dose oral combination therapy to treat chronic hepatitis C virus (HCV) genotype 1 infection that does not require interferon or ribavirin. The agency approved the once-daily combination of Gilead's HCV NS5A replication inhibitor ledipasvir, plus its nucleotide analog HCV NS5B polymerase inhibitor Sovaldi (sofosbuvir) on October 10, as a new chemical entity, with exclusivity through 2019. A 12-week course of Harvoni will cost $94,500, similar to the price of Sovaldi, interferon and ribavirin combined. The company has been criticized over the price of Sovaldi, approved in December 2013 in combination with other therapies to treat HCV genotypes 1, 2, 3 and 4.