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.


OBJECTIVE
To characterize safety and efficacy of an enfuvirtide to raltegravir switch including changes in T-cells, quality of life, and residual viremia.


METHODS
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.
Grant
Philip M
PM
Stanford University, Division of Infectious Diseases, Palo Alto, CA 94305-5107, USA. pmgrant@stanford.edu
Palmer
Sarah
S
Bendavid
Eran
E
Talbot
Annie
A
Slamowitz
Debbie C
DC
Cain
Pat
P
Kobayashi
Stacy S
SS
Balamane
Maya
M
Zolopa
Andrew R
AR
D018791:CD4 Lymphocyte Count; D000077560:Enfuvirtide; D015700:HIV Envelope Protein gp41 / Q000627:therapeutic use*; D023581:HIV Fusion Inhibitors / Q000627:therapeutic use*; D015658:HIV Infections / Q000188:drug therapy*; D015497:HIV-1 / Q000187:drug effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D010446:Peptide Fragments / Q000627:therapeutic use*; D011446:Prospective Studies; D011760:Pyrrolidinones / Q000627:therapeutic use*; D011788:Quality of Life; D000068898:Raltegravir Potassium; D016896:Treatment Outcome; D019562:Viral Load; D014766:Viremia / Q000188:drug therapy*
D015700:HIV Envelope Protein gp41; D023581:HIV Fusion Inhibitors; D010446:Peptide Fragments; D011760:Pyrrolidinones; D000077560:Enfuvirtide; D000068898:Raltegravir Potassium