A prospective randomized controlled trial of structured treatment interruption in HIV-infected patients failing highly active antiretroviral therapy (Canadian HIV Trials Network Study 164).
OBJECTIVE
To determine prospectively the impact of switching treatment-experienced patients with virologic failure to a salvage regimen with or without a 12-week structured treatment interruption (STI). The primary endpoint was the percentage of patients with a 3-month sustained HIV RNA level <50 copies/mL.


METHODS
A randomized, open-label, multicenter trial. At least 2 new antiretroviral (ARV) drugs, based on patient history, were included in the salvage regimen, as determined before randomization and guided by resistance testing.


RESULTS
A total of 147 patients were randomized: 79 to the immediate switch (IS) arm and 68 to the STI arm. Success was achieved by 64% in the IS arm and 51% in the STI arm (95% confidence interval for the difference from 5% in favor of STI to 30% in favor of IS). During the STI, the median decrease in CD4 count was 80 cells/mm and the increase in viral load was 0.8 log10 copies/mL. There were no differences in median CD4 cell counts or HIV RNA levels at week 60. Two unrelated deaths (1 in each arm) and 3 AIDS-defining events (in the STI arm) occurred.


CONCLUSIONS
A 12-week STI before the initiation of salvage ARV therapy did not increase the proportion of patients with 3 months of sustained suppression of HIV RNA to <50 copies/mL.
Walmsley
Sharon L
SL
Department of Medicine, University of Toronto, 200 Elizabeth Street, Toronto, Ontario, Canada. sharon.walmsley@uhn.on.ca
Thorne
Anona
A
Loutfy
Mona R
MR
LaPierre
Natasha
N
MacLeod
John
J
Harrigan
Richard
R
Trottier
Benoit
B
Conway
Brian
B
Hay
Joy R
JR
Singer
Joel
J
Zarowny
Don
D
D000328:Adult; D019380:Anti-HIV Agents / Q000008:administration & dosage* / Q000627:therapeutic use; D023241:Antiretroviral Therapy, Highly Active; D004334:Drug Administration Schedule; D005260:Female; D015658:HIV Infections / Q000188:drug therapy* / Q000821:virology; D015497:HIV-1 / Q000187:drug effects / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012367:RNA, Viral / Q000097:blood; D018894:Reverse Transcriptase Inhibitors / Q000008:administration & dosage* / Q000627:therapeutic use; D016879:Salvage Therapy; D017211:Treatment Failure; D016896:Treatment Outcome
D019380:Anti-HIV Agents; D012367:RNA, Viral; D018894:Reverse Transcriptase Inhibitors