A randomized placebo-controlled trial of adefovir dipivoxil in advanced HIV infection: the ADHOC trial

Abstract

Objectives: To assess the efficacy and safety of adefovir dipivoxil (ADV) added to stable background antiretroviral therapy (ART) in HIV-infected individuals with advanced HIV disease.

Methods: ADHOC was a randomized, double-blind, placebo-controlled, international multicentre trial. Three hundred and one individuals with CD4 cell counts < 100 cells/microL or < 200 cells/microL with nadir < 50 cells/microL were allocated to receive either 120 mg ADV (subsequently 60 mg) (n = 161) or matching placebo (n = 140) once daily.

Results: Over a median follow-up of 76 weeks, 23 (14%) and 18 (13%) participants assigned ADV and placebo, respectively, developed a new AIDS event or died (hazard ratio = 1.23, 95% confidence interval 0.66-2.29, P= 0.51). There was a lower incidence of new or recurrent herpes events in the ADV group (P = 0.009). The mean increase in CD4 cell count from baseline to week 24 was 23.0 and 24.4 cells/ micro L in ADV and placebo groups, respectively (P = 0.89), and the mean decrease in RNA was 0.32 and 0.35 log10 copies/mL at week 24 (P = 0.87) in a subset of participants. There was greater weight loss in the ADV group during the trial (P = 0.007). One hundred and twenty-four participants (41%) had stable background ART in the 8 weeks prior to and the 24 weeks after randomization. There was no significant imbalance in background ART regimens between the two treatment groups. Ninety-seven serious adverse events (SAEs) occurred, 65 and 32 in the ADV and placebo groups, respectively, with significantly shorter time to first SAE in the ADV group (P = 0.002). A total of 33 participants developed proximal renal tubular dysfunction during the trial, all but one in the ADV group.

Conclusions: Due to the early termination of recruitment, ADHOC was unable to assess the original objective of clinical disease progression. Adding ADV to background antiretroviral therapy in advanced HIV disease did not provide immunological or virological improvement compared with placebo. Furthermore, at the doses used in this trial, ADV was associated with a significantly higher incidence of SAEs.