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  AIDS 2002 Barcelona
Barcelona, Spain July 7-12 2002
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Tenofovir vs d4T: 48 Week Study Results in Treatment Naïve
Reported by Jules Levin
  This study shows Tenofovir is as potent as d4T in a triple combination regimen in combination with efavirenz and 3TC in patients who never before received HIV treatment.
At today's final conference session at 8:30am the oral Late Breakers were presented. The first presentation was on the 48 week results from the study of Tenofovir (Viread) vs d4T (Stavudine) when used in combination with 3TC and efavirenz. This study was conducted in treatment-naïve patients. This is the first large study using Tenofovir (TDF) in treatment-naïve patients. Previous studies used the drug in patients with extensive previous use of treatment & with NRTI resistance. A short 21 day study of TDF monotherapy has demonstrated a 1.5 log reduction in viral load in treatment-naïve patients.
In Study 903 600 treatment-naïve patients received either: TDF once daily + efavirenz once daily + 3TC twice daily or d4T twice daily + efavirenz once daily + 3TC twice daily. By the way, 3TC was just approved by the FDA to be taken once daily. This study will run for 144 weeks and responses are reported for patients with >100,000 copies viral load and <100,000 copies viral load. As well, responses are reported for patients with >200 Cd4s or <200 CD4s.
Although it wasn't presented today, this study will be conducting substudies on hepatitis, lipodystrophy, bone mineral density, and lactate.
There are about 300 patients in each arm of the study. Baseline characteristics of the patients are comparable in each arm. About 25% of patients are female. 84% white. HIV viral load 81,300 copies. CD4s 270. 43% had >100,000 copies of viral load. 39% had <200 CD4s.
The discontinuation rate appears low at 9% in each arm.
After 48 weeks of therapy 87% in both arms had <400 copies/ml of viral load (ITT, missing=failure). 82% in each arm had <50 copies/ml (ITT, m=f). These data suggest that TDF is comparable to d4T in a firstline therapy. CD4s increased about 168 in each arm.
TDF and d4T regimens were equally effective, when looking at percent <400 copies, in patients with above or below 100,000 copies viral load, and in patients with above and below 200 CD4s.
The percent of patients experiencing grade 3/4 adverse events was the same in both arms - 18%. And there did not appear to be major differences between the arms.
ucleoside Toxicities
Investigators reported more toxicities in the d4T arm (11% vs 3%). Peripheral neuropathy: 2% in TDF arm vs 7% in d4T arm. Lipodystrophy: 1% in TDF arm vs 4% in d4T arm. Lactic acidosis: 0% in TDF arm vs 1% in d4T arm. 0 pancreatitis in each arm.
There was no difference between the arms in grade 3/4 lab abnormalities 28% in TDF arm & 31% in d4T arm.
At week 48, triglycerides increased 74 mg/dL in the d4T arm but not at all in the TDF arm, and this was siginficant.
Similarly for cholesterol at week 48, increase was significantly greater in d4T arm than TDF arm (53 mg/dL vs 25 mg/dL).