Adding Maraviroc to Antiretroviral Therapy for Suboptimal CD4 T-Cell Recovery Despite Sustained Virologic Suppression

The majority of HIV-infected subjects with virologic suppression on antiretroviral therapy (ART) have a marked increase in CD4+ T-cell counts over the first year on treatment. However, a portion of these individuals show a suboptimal immune response and remain at an elevated risk for disease progression. The use of the CCR5 inhibitor maraviroc (MVC) is associated with enhanced CD4+ T-cell recovery in subjects who initiate ART. AIDS Clinical Trials Group (ACTG) A5256 studied the effect of ART intensification with MVC on CD4+ T-cell counts in subjects with suboptimal CD4 recovery despite sustained virologic suppression. Eligible subjects added MVC to their ART regimen, and continued MVC for 24 weeks. At week 24, subjects discontinued MVC and were followed for an additional 24 weeks off MVC. Subjects were seen through week 48 for clinical and laboratory evaluations, including plasma HIV-1 RNA, CD4+ T-cell count, and safety laboratories. Subjects had 2 baseline visits prior to starting MVC. Study visits were scheduled at weeks 4, 8, 12, 16, 22, 24, 36, 46, and 48. CD4+ T-cell counts were measured at every study visit and HIV-1 RNA at weeks 12, 24, 36, and 48, regardless of treatment status. Measures of activation, T-cell maturation, and apoptosis were performed at all weeks except 4, 8, and 16. At the end of the study, the pre-entry, entry, week 12, 22, 24, and 36 samples for the HIV-1 RNA by single-copy assay (SCA) were run. The week 46 and 48 samples were not run.