Progression to AIDS or death as endpoints in HIV clinical trials

Abstract

Purpose: To assess progression to AIDS or death from month 4 after a protease inhibitor-containing regimen is initiated in a cohort of 1,281 patients. Method: We used Kaplan-Meier estimates of probability of clinical progression. Result: At month 4, most patients had an HIV-1 RNA plasma value below 500 copies/mL (78%) and a CD4 cell count above 300 cells/mm3 (62%). Starting from month 4, clinical progression at 1 and 2 years of follow-up was low (<3% at 1 year) in patients with HIV RNA <500 copies/mL or 500-10,000 copies/mL and in patients with CD4 between 50 and 300 cells/mm3 or >300 cells/mm3. A higher risk of clinical progression (≥10% at 1 year) was evidenced only in patients with poor response to antiretroviral therapy, that is, with CD4 <50 cells/mm3 or CD4 between 50-300 cells/mm3 together with an HIV RNA > 10,000 copies/mL. Conclusion: In patients currently on antiretroviral therapy, clinical trials with clinical progression as endpoint are almost not feasible, except in patients with a poor immunovirological response to first- or second-line HAART.