Elvucitabine is an experimental nucleoside reverse transcriptase inhibitor (NRTI), developed by , Inc. for the treatment of HIV infection. Elvucitabine belongs to a class (group) of HIV drugs called nucleoside reverse transcriptase inhibitors (NRTIs). NRTIs block an HIV enzyme called reverse transcriptase. (An enzyme is a protein that starts or increases the speed of a chemical reaction). By blocking reverse transcriptase, NRTIs prevent HIV from multiplying and can reduce the amount of HIV in the body. Currently, it is in Phase II clinical trials.