Gilead Sciences Inc. announced that the European Commission has granted marketing authorization for Vemlidy (tenofovir alafenamide, TAF) 25 mg, a once-daily tablet for the treatment of chronic hepatitis B virus (HBV) infection in adults and adolescents (aged 12 years and older with body weight at least 35 kg). The marketing authorization allows for the marketing of TAF in the 28 countries of the European Union, Norway and Iceland. TAF is a novel, targeted prodrug of tenofovir that has demonstrated antiviral efficacy similar to Gilead’s Viread® (tenofovir disoproxil fumarate, TDF) 245 mg, but at one-tenth the dose. Data show that because TAF has greater plasma stability and more efficiently delivers tenofovir to hepatocytes (cells of the liver) compared to TDF, it can be given at a lower dose, which means there is less tenofovir in the bloodstream. By reducing exposure to tenofovir, TAF is associated with improved renal and bone laboratory safety parameters compared to TDF in clinical trials.