Ibalizumab for the treatment of multidrug-resistant HIV-1 infection

Ibalizumab, a humanized monoclonal antibody to CD4, was recently approved by the United States Food and Drug Administration (FDA) for the treatment of HIV-1 infection in heavily treatment-experienced adults with multidrug-resistant HIV-1 infection failing their current antiretroviral regimen. Ibalizumab is the first in a new class of antiretroviral drugs designated as post-attachment inhibitors. It exerts its antiviral effect by noncompetitive binding of CD4, thereby blocking conformational changes in the CD4-gp120 complex that are essential for viral entry. Clinical studies have demonstrated ibalizumab's significant antiviral activity in patients with advanced HIV disease and extensive treatment experience, who had limited treatment options. Ibalizumab is administered intravenously at a dose of 800 mg every 2 weeks following a single intravenous loading dose of 2000 mg. The most common adverse reactions reported with the use of ibalizumab are diarrhea, dizziness, nausea and rash.