Azvudine (RO-0622) is a novel nucleoside reverse transcriptase inhibitor with antiviral activity against human immunodeficiency virus (HIV), hepatitis B virus (HBV) and hepatitis C virus (HCV), potently inhibits HIV-1 (EC50 range 0.03 to 6.92 nM) and HIV-2 (EC50s ranging from 0.018 to 0.025 nM).