Enfuvirtide (T-20, Fuzeon)

T-20 (enfuvirtide, Fuzeon) is the first of a new class of drugs called fusion inhibitors, so called because they stop HIV from binding to and entering the human cell. Once HIV has attached to a receptor, it needs to bind to glycoprotein 41 (gp41) on the cell surface. T-20 binds to gp41, preventing HIV from entering the CD4 cell .

European and United States drug regulatory authorities granted accelerated approval for T-20 in March 2003. It has been approved for use in individuals who have experienced failure of at least one drug from each existing class of antiretrovirals, or who have intolerance to previous antiretroviral regimens. Traditional approval in the United States was granted in October 2004.

British HIV Association (BHIVA) guidelines advise that T-20 should be used with two or more other active drugs, rather than as an add-on to a failing regimen, in order to reduce the chance of resistance developing. However, they also point out that it is substantially more expensive than any other antiretroviral drug.

A recent analysis of the health-related quality of life measures of participants in the two TORO studies has revealed that addition of T-20 to an optimised background regimen does not adversely affect any aspect of quality of life, and may improve general health and mental health status.1

There are no known clinically significant interactions between T-20 (enfuvirtide, Fuzeon) and any other medications.


  1. Cohen C et al. Selection of non-enfuvirtide (ENF) vs ENF-containing regimens leads to higher failure rates and loss of future antiretroviral treatment options. 44th Interscience Conference on Antimicrobial Agents and Chemotherapy, Washington, abstract H-580, 2004