Tenofovir alafenamide (INN/USAN, formerly GS-7340) is a nucleotide reverse transcriptase inhibitor and a prodrug of tenofovir. It was developed by Gilead Sciences for use in the treatment of HIV infection and chronic hepatitis B, and is applied in the form of tenofovir alafenamide fumarate (TAF). Closely related to the commonly used reverse-transcriptase inhibitor tenofovir disoproxil, TAF has greater antiviral activity and better distribution into lymphoid tissues than that agent.