Tenofovir alafenamide in the treatment of chronic hepatitis B: design, development, and place in therapy

Eiichi Ogawa,1 Norihiro Furusyo,1 Mindie H Nguyen2 1Department of General Internal Medicine, Kyushu University Hospital, Fukuoka, Japan; 2Division of Gastroenterology and Hepatology, Department of Medicine, Stanford University Medical Center, Palo Alto, CA, USA Abstract: Tenofovir alafenamide (TAF), a novel prodrug of tenofovir (TFV), has been approved for the treatment of chronic hepatitis B virus (HBV) infection. TAF has been shown to be a potent inhibitor of HBV replication at a low dose, with high intracellular concentration and more than 90% lower systemic TFV concentration than tenofovir disoproxil fumarate (TDF). In two randomized, double-blind, multinational, Phase 3, non-inferiority trials for hepatitis B e antigen (HBeAg)-positive and -negative patients (primary analysis: 48 weeks), TAF 25 mg orally once-daily was not inferior to TDF 300 mg in achieving an HBV DNA level