Gilead Sciences, Inc. GILD announced that the FDA has approved Vosevi (Sovaldi, velpatasvir 100 mg/voxilaprevir 100 mg) tablets. The drug is a single-tablet regimen (STR) for the re-treatment of chronic hepatitis C virus (HCV) infection in adults with genotype 1, 2, 3, 4, 5 or 6, previously treated with an NS5A inhibitor-containing regimen, or with genotype 1a or 3 previously treated with a Sovaldi-containing regimen without an NS5A inhibitor.The approval came on the back of positive data from the phase III studies – POLARIS-1 and POLARIS-4 studies. The studies evaluated 12 weeks of Vosevi in direct-acting antiviral-experienced chronic HCV-infected patients without cirrhosis or with compensated cirrhosis.However, Vosevi has been warned for its product label regarding the risk of hepatitis B virus (HBV) reactivation in HCV/HBV co infected patients.Nevertheless, the approval makes Vosevi the first once-daily STR available as a salvage therapy for patients infected with HCV genotype 1–6 who have failed prior treatment with DAA regimens including NS5A inhibitors. The approval is expected to boost Gilead’s strong HCV portfolio.Gilead has a strong presence in the HCV market due to its blockbuster HCV drugs, Sovaldi and Harvoni. While Sovaldi continues to be a very important product for the company, Harvoni’s label has been expanded twice in the U.S. since approval and is now approved for use in a broader range of patient population. The HCV portfolio got a huge a boost when Epclusa gained approval in both the U.S. (Jun 2016) and the EU (Jul 2016) to become the first and only all-oral, pan-genotypic, STR consisting of Sovaldi and velpatasvir (an NS5A inhibitor), for the treatment of adults with genotype 1-6 chronic HCV infection. Initial uptake of Epclusa has been encouraging while formulary reviews are on track. Gilead expects to launch Epclusa in other large EU markets once pricing and reimbursement is in place by the second half of 2017, which should boost sales further.Last month, the Committee for Medicinal Products for Human Use (CHMP) adopted a positive opinion on the company’s Marketing Authorization Application (MAA) for Vosevi following an accelerated assessment procedure.Gilead’s HCV franchise is under pressure due to intense competition and pricing issues. HCV product sales were weaker than expected mainly due to fewer new patient starts for Harvoni and lower revenues per patient. Harvoni, Sovaldi and Epclusa has being facing competition from AbbVie’s ABBV Viekira Pak and Viekira XR, Bristol-Myers’ BMY Daklinza and Johnson & Johnson’s JNJ Olysio.The company expects that the persistent decline in HCV patient starts will be the primary factor behind the year-over-year decrease in revenues in 2017 along with increased competition which will impact patient share and pricing.Shares of Gilead have underperformed the Zacks classified Medical-Biomedical and Genetics industry in the year so far, with the stock losing 0.1% during this period, against the industry’s gain of 8.8%. Nevertheless, the HIV franchise of Gilead is performing well and is expected to help the company combat the persistent decline in HCV franchise.Zacks Rank Gilead currently carries a Zacks Rank #3 (Hold).You can see the complete list of today’s Zacks #1 Rank stocks here.Looking for Stocks with Skyrocketing UpsiZacks has just released a Special Report on the booming investment opportunities of legal marijuana.Ignited by new referendums and legislation, this industry is expected to blast from an already robust $6.7 billion to $20.2 billion in 2021. Early investors stand to make a killing, but you have to be ready to act and know just where to look. See the pot trades we're targeting>>Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report Bristol-Myers Squibb Company (BMY): Free Stock Analysis Report Johnson & Johnson (JNJ): Free Stock Analysis Report AbbVie Inc. (ABBV): Free Stock Analysis Report Gilead Sciences, Inc. (GILD): Free Stock Analysis Report To read this article on Zacks.com click here. Zacks Investment Research