Rifaximin as a Modulator of Microbial Translocation and Immune Activation

A5286 is a randomized, open-label, two-arm, pilot (phase II) study that evaluated whether 4 weeks of treatment with rifaximin, a non-absorbable antibiotic, decreases markers of immune activation and levels of translocated gut microbial products in HIV-1 infected subjects virally suppressed on ART with CD4+ T-cells \< 350 cells/mm\^3. Rifaximin were admistered to subjects for 3 weeks. Follow-up continued to week 12. The total sample size was 73 subjects. Subjects were randomized at a 2:1 ratio (rifaximin: no study treatment), using permuted blocks, without institutional balancing. Subjects were seen through week 12 for clinical and laboratory evaluations, including plasma HIV-1 RNA, CD4+ T-cell count, and safety laboratories. Subjects had 2 baseline visits -- at pre-entry and entry. Study visits were scheduled at weeks 2, 4, 8, and 12. CD4+ T-cell counts and HIV-1 RNA were measured at all weeks; measures of activations, gut-homing markers, and soluble biomarkers were also performed at all weeks.