48-Week Amprenavir Update

This randomized, double-blind, phase III study compares amprenavir (APV) plus AZT/3TC to AZT/3TC in treatment-nave individuals. Participants with viral load >400 copies/ml at week 16 were permitted to switch to open-label APV. 221 of the 232 randomized received treatment.

Baseline median viral load and CD4 in the APV arm were 44,000 copies/ml and 442 in the APV + AZT/3TC arm.

Viral Load Results:

APV Viral Load Changes By Baseline Viral Load (See Table 15):  

Table 15.

Baseline Viral Load

As Treated Analysis <400

<400 ITT

10,000 30,000

87% (20/23)

51% (19/37)

30,000-100,000

24/24 (100%)

42% (23/55)

>100,000

86% (6/7)

25% (6/24)

Investigators reported an ITT Observed Data analysis (<50 copies/ml) which is not as stringent as an ITT analysis but also not as liberal as an as-treated analysis. At week 16, 59% had <50 copies/ml (n=88).  At week 48 they reported 69% had <50 copies but this included individuals who switched to APV after week 16 because their viral load was >400 copies/ml.

Adverse Events.  Investigators reported the incidence of treatment-related adverse events of at least moderate intensity through week 48:

Lipids and Lipodystrophy.  They reported there were no grade 3 or 4 elevations in triglycerides or cholesterol (n=113) and 1 person had hyperglycemia. One case of abnormal fat redistribution has been reported to date. The subject received over 1 year of APV and remains in study with undetectable VL.  Because the study population is treatment-nave they might be less prone to develop lipodystrophy and one year may not be enough time for lipodystrophy to develop.