Enfuvirtide, a new treatment for HIV infection.

Enfuvirtide is the first in a new class of drugs called fusion inhibitors. It was recently approved in Canada for the treatment of patients with evidence of HIV-1 replication despite ongoing antiretroviral therapy. Current evidence on safety and efficacy is limited to 48-week studies. Two phase III trials found that in treatment-experienced patients failing antiretroviral treatment, the addition of subcutanous enfuvirtide to an optimized oral background antiretroviral regimen significantly reduced viral load and increased CD4 cell counts. Potential high cost and limited supply may reduce access to this treatment.