Avanti II was the second in a series of small international studies designed to investigate multi-drug combinations in antiretroviral-naive volunteers, and identify the most promising regimens for testing in large clinical trials. This trial tested AZT plus 3TC versus AZT plus 3TC plus indinavir.
This was an international, double-blind (neither doctors nor volunteers knew which therapy volunteers received), comparative trial where volunteers, with CD4 count between 150 and 500 cells/mm3, were randomized to receive either AZT(200mg td)/3TC(150mg bd) or AZT/3TC/indinavir(800mg q8h) for 52 weeks. Volunteers were assessed regularly to determine the degree and duration of viral load reduction, changes in CD4 count and the safety and tolerance of the treatment regimens.
One hundred and three volunteers from Europe, Canada and Australia were randomly assigned to receive either treatment regimen. The median baseline viral load (log(10) copies/ml) was 4.5 for the AZT/3TC group and 4.8 for theAZT/3TC/indinavir group, while the median baseline CD4 count was 270 and 280 respectively.
At week 52, the percentage of volunteers who had viral loads below 500 copies/ml was 23% in the two-drug arm and 75% in the three-drug arm. The maximum median decrease in viral load occurred at week 4 in the AZT/3TC group and was -2.4, while it occurred at week 12 in the AZT/3TC/indinavir and was -3.2.
Both groups showed an increase in CD4 count that was sustained over the study period. In the AZT/3TC group, the maximum median increase was 95 cells/mm3 at week 40 while at week 52 the value was 78 cells/mm3. The AZT/3TC/indinavir group showed a maximum median increase of 179 cells/mm3 at week 40, 177 cells/mm3 at week 52.
These 52-week data are the first in naive patients which compare AZT/3TC and AZT/3TC/indinavir. Both the AZT/3TC group and the AZT/3TC/indinavir group demonstrated a sustained antiviral effect when measuring viral load and CD4 count. In the triple combination 75% of patients had viral loads below 500 copies/ml at week 52 and the median CD4 increase at this time point was 177 cells/mm3. These encouraging data are in line with that already presented for antiretroviral experienced volunteers with the combination of AZT/3TC/IDV.
Note: These results were taken from abstract 211 of the 6th European conference on Clinical Aspects and Treatment of HIV-Infection, Hamburg 1997.