Maraviroc as an Immunomodulatory Drug for Antiretroviral-treated HIV Infected Patients Exhibiting Immunologic Failure

Our primary hypothesis is that CCR5 inhibitors may have protective immunomodulatory effects independent of their impact on HIV replication. Specifically, we predict that maraviroc will reduce the persistent T cell activation that prevents normal immune reconstitution during HAART-mediated viral suppression. This hypothesis will be tested in the context of a placebo controlled pilot study assessing the impact of maraviroc in antiretroviral-treated patients with a CD4+ T cell count less than 350 cells/mm3. In order to address the immunologic activity of this drug independent of plasma HIV RNA levels, we will study individuals who have undetectable viral loads (\< 75 copies RNA/mL). Subjects will be randomized to maraviroc for 24 weeks or matching placebo for 24 weeks, followed by a 12 week washout period. We will use as our primary endpoint the proportion of CD8+ T cells that co-expresses CD38 and HLA-DR, as these outcomes have been well validated in prior studies. The primary outcome will be change in the percentage of activated CD8+ T cells at week 24. Change in CD4+ T cell counts, HIV RNA levels (using ultra-sensitive techniques), and other more experimental immunologic measurements will be assessed as secondary outcomes.