Switch from enfuvirtide to raltegravir in virologically suppressed HIV-1 infected patients: effects on level of residual viremia and quality of life.

BACKGROUND: Raltegravir is a potential treatment option for virologically suppressed HIV-1 infected patients on enfuvirtide with injection site reactions.
OBJECTIVES: To characterize safety and efficacy of an enfuvirtide to raltegravir switch including changes in T-cells, quality of life, and residual viremia. STUDY
DESIGN: In patients with viral load <50 copies/mL and injection site reactions, enfuvirtide was switched to raltegravir without additional changes to the antiretroviral regimen. Virologic failure was defined as a viral load >1000 copies/mL or two consecutive viral load measurements between 50 and 1000 copies/mL (low-level viremia). Over the 24 week study, we compared changes in T-cells, injection site reactions, quality of life, and residual viremia, as measured through the single-copy assay which can detect plasma virus down to a single copy, using paired t-tests.
RESULTS: Fourteen patients with a median CD4+ T-cell count of 420 cells/microL were enrolled. After the switch, two patients experienced virologic failure due to confirmed low-level viremia. However, both patients subsequently were re-suppressed, one without any changes to his regimen. There was no change in CD4+ T-cell count. Injection site reactions resolved. However, there was little reported change in quality of life. The baseline median level of residual viremia was 6 copies/mL and did not change after the switch to raltegravir.
CONCLUSIONS: A switch to raltegravir in virologically suppressed patients on enfuvirtide is effective in maintaining immunologic and virologic control at 24 weeks but did not result in a change in residual viremia.