Gilead Sciences, Inc. (Nasdaq: GILD) today announced that the U.S. Food and Drug Administration (FDA) has approved Vemlidy ® (tenofovir alafenamide, TAF) 25mg, a once-daily treatment for adults with chronic hepatitis B virus (HBV) infection with compensated liver disease. Vemlidy has a boxed warning in its product label regarding the risks of lactic acidosis/severe hepatomegaly with steatosis and post-treatment severe acute exacerbation of hepatitis B. See below for important safety information. Vemlidy is a novel, targeted prodrug of tenofovir that has demonstrated antiviral efficacy similar to and at a dose less than one-tenth that of Gilead's Viread ® (tenofovir disoproxil fumarate, TDF) 300mg. Data show that because Vemlidy has greater plasma stability and more efficiently delivers tenofovir to hepatocytes compared to Viread, it can be given at a lower dose, resulting in less tenofovir in the bloodstream. As a result, Vemlidy improved renal and bone laboratory safety parameters compared to Viread. "Chronic hepatitis B is a life-threatening illness that affects up to 2.2 million people in the U.S.," said Calvin Pan, MD, Clinical Professor of Medicine, NYU Langone Medical Center, and investigator in the Vemlidy clinical trials. "Clinical trials demonstrated Vemlidy is efficacious with improved renal and bone safety parameters compared to Viread, representing an important development for people living with this chronic disease." Photos and multimedia gallery available at www.GileadHBVMedia.com. Vemlidy's approval is supported by 48-week data from two international Phase 3 studies (Studies 108 and 110) among 1,298 treatment-naïve and treatment-experienced adult patients with chronic HBV infection. Study 108 randomized and treated 425 HBeAg-negative patients with either Vemlidy or Viread, and Study 110 randomized and treated 873 HBeAg-positive patients with either Vemlidy or Viread. Both studies met their primary endpoint of non-inferiority to Viread based on the percentage of patients with chronic hepatitis B with plasma HBV DNA levels below 29 IU/mL at 48 weeks of therapy.