Factors associated with virological response to a switch regimen containing maraviroc for antiretroviral-experienced HIV-1-infected patients.

Abstract

There are few data on clinical and virological factors associated with maraviroc virological response (VR) in clinical practice. This study aimed to identify factors associated with VR in 94 treatment-experienced, but CCR5 inhibitor-naive, HIV-1 patients switched to maraviroc-containing regimens. Patients with HIV-1 RNA viral load (VL) <50 copies/mL switching to an antiretroviral treatment containing maraviroc were followed. VR was defined at month 3 as VL <50 copies/mL. The impact of age, baseline tropism, zenith VL, nadir CD4 cell count and CD4 cell count, HIV subtype (B versus non-B), genotypic susceptibility score of treatment, once- or twice-daily treatment and presence of raltegravir in optimized background therapy on VR was investigated. Baseline characteristics were: median age 49 years (range 25-73 years), median CD4 cell count 481 cells/mm(3) (range 57-1830 cells/mm(3)) and median nadir CD4 cell count 99 cells/mm(3) (range 3-585). Maraviroc was administered twice daily in 88 of 94 patients and once daily in 6 of 94 patients (300 mg/day for 4 of 6 and 150 mg/day for 2 of 6). At month 3, 89.4% of patients were responders. A better VR to a switch regimen containing maraviroc was associated with the B subtype (P = 0.0216) and a lower zenith VL (median of 5.24 and 5.70 log10 copies/mL for patients in success or in failure, respectively) in univariate analysis. Only B subtype was associated with a better VR in multivariate analysis. This study evidenced the efficacy of a switch regimen containing maraviroc in clinical practice. VR was better for patients with a lower zenith VL and B subtype.