Gilead announced on Monday that the FDA has granted priority review to the combination of sofosbuvir (Sovaldi) and velpastavir, which has shown promising advances in the treatment of hepatitis C virus (HCV).

It’s anticipated that the FDA will come to a final decision by June of this year. The New Drug Application for the combination therapy included data from four Phase 3 ASTRAL trials. These trials studied the fixed-dose combination of the drugs in the treatment of HCV genotypes 1-6.

Sofosbuvir is a nucleotide analog polymerase inhibitor, while velpastavir is an investigational pan-genotypic NS5A inhibitor.

A marketing strategy was validated by the European Medicines Agency in December and is currently under review in the European Union. The safety and efficacy of the combination has yet to be established.