Enfuvirtide (EFV)

Enfuvirtide is an HIV fusion inhibitor, the first of a novel class of antiretroviral drugs used in combination therapy for the treatment of HIV-1 infection. Enfuvirtide works by disrupting the HIV-1 molecular machinery at the final stage of fusion with the target cell, preventing uninfected cells from becoming infected. A biomimetic peptide, enfuvirtide was designed to mimic components of the HIV-1 fusion machinery and displace them, preventing normal fusion. Drugs that disrupt fusion of virus and target cell are termed entry inhibitors or fusion inhibitors. Enfuvirtide is considered to be active against HIV-1 only. Low activity against HIV-2 isolates has been demonstrated in vitro. Variable susceptibility to enfuvirtide has been observed in clinical isolates, with acquired resistance the result of a mutated 10 amino acid motif in viral gp41. Primary resistance, however, has yet to be observed.