NRTI-only
Regimen of Trizivir Plus Tenofovir May Be a Viable Option for Treatment-experienced
Patients with Lower HIV Viral Loads
Researchers
investigated the virologic response to a simple, NRTI-only
combination therapy consisting of tenofovir/TDF (Viread) and abacavir/lamivudine/zidovudine
(ABC/3TC/AZT)
[Trizivir (TZV)] in heavily ART-experienced patients. In a retrospective study, investigators
searched their database of all therapy-experienced patients taking tenofovir/Trizivir/
TDF/TZV who had at least one lab value after start of therapy and 24 weeks of
follow-up. Ninety-four
patients qualified for this study. Virologic response
was defined as viral load levels less than 400 copies/ml by week 24. Results 
Median baseline characteristics include:
age 43, exposed to 7 drugs, 6.5 years of therapy. 17 females were included (18%).
The patients were, in
general, doing well at baseline with a median viral load of 371 copies/ml and a CD4 count of 289 cells/mm³.
Median
follow up is 41 weeks (2-271).
At
week 24, 80/94 (85%) pts were still on TDF/TZV treatment.
Results
from an intent-to-treat analysis demonstrated a median CD4 count of 345 CD4 cells/mm³ and a median viral load of 69 copies/ml.
66/94
pts (70%) reached <400 copies.
18
patients had viral loads greater than 100,000 copies at baseline. These patients
tended to fare poorer with only 8/18 (44%) responding virologically to TDF/TZV by week 24; 4 of these 8 had less
than 50 copies.
29
patients had at least 3 nucleoside-associated mutations (TAMS, M184V, E44D, K65R,
L74V, Y115F, V118I, or MDR mutations) either at baseline or during prior therapies,
or both.
17
of the 29 (59%) were still able to reach undetectable viral load levels by week
24.
Based
on these findings, the authors conclude, “The simple combination therapy TDF plus
TZV may be a viable, longer-term option in highly ART-experienced patients with
lower viral loads.” “85%
of our patients in this study were still on treatment after 24 weeks and 70% demonstrated
a virologic response to less than
400 copies/ml.” 01-13-05 Reference
B Dauer and others.
Virologic Response to Tenofovir
DF (TDF) Plus Trizivir (TZV)
Therapy in Heavily ART-Experienced, HIV+ Patients: 24 Week Results. Abstract H-520. Abstracts
of the 45th Interscience Conference on
Antimicrobial Agents and Chemotherapy. December 16-19, 2005. Washington, DC.
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