This multicenter, randomized, open label clinical trial enrolled ARV-na茂ve HIV patients with CD4 counts below 500 cells/mm3. They were randomly assigned to start ddI + d4T + nelfinavir (switching to ZDV + 3TC + NEV in case of failure or toxicity) (PI-NEV arm) or ddI + d4T + nevirapine, switching to ZDV + 3TC + NFV in case of failure or toxicity (NEV-PI arm). The primary study endpoint was the Kaplan-Meier estimates of the time to failure after switching to second regimen if necessary (considering failure as two consecutive plasma HIV-1 RNA determinations above 200 copies/mL, death, a new category C event or toxicity leading to treatment discontinuation of the second regimen) after a minimum follow-up of two years.
A total of 137 patients were evaluable (67 and 70 in the PI-NEV and NEV-PI arms respectively). Baseline characteristics did not differ among groups. Kaplan-Meier estimates of time to failure did not show differences between the two arms neither in the on-treatment (OT) analysis (log rank test, p = 0.81) nor in the intent-to-treat (ITT) analysis (p = 0.58). At 24 months, the estimated proportion of patients free of failure were 72%and 66%respectively in the PI-NEV and NEV-PI arms OT analysis (p = 0.54) and 73%and 64%in the PI-NEV and NEV-PI arms in the ITT analysis (p = 0.49). The difference in the median in CD4+ lymphocyte count at 24 months was not significantly different in the two groups: 393 and307 CD4 cells/mm3 in the PI-NEV and NEV-PI arms respectively (p = 0.167).
The incidence of adverse events (AEs) in the two arms was very similar: 50 (75%) in the PI-NEV and 54 (70%) in the NEV-PI group, as it was for grade 3-4 AEs leading to drug switching.
At two years both treatments strategies (PI-NEV vs NEV-PI) had a high and comparable efficacy and were generally well tolerated.