MONOI Study: Switch to DRV/r bid monotherapy

Katlama C. AIDS. 2010 Sep 24;24(15):2365-74 ; Marcelin AG. CROI 2011; Abs.533

Type of ARV Trial
Switch studies in virologically suppressed patients
» Switch to PI/r monotherapy
» DRV/r mono vs DRV/r + 2 NRTI
PI/r mono, DRV/r, 2 NRTI


  • From W48 results
    • Because of the discordance between per-protocol and ITT analysis, DRV/r bid monotherapy was not non inferior to DRV/r bid + 2 NRTI, in patients with virologic suppression on prior ARV regimen
    • Sub-group analysis showed that the difference in efficacy favouring the triple arm therapy was larger in patients with a high level of pre-therapy HIV-1 RNA
    • A higher proportion of intermittent viremia was seen in patients randomised to DRV/r monotherapy, but no DRV resistance mutations emerged
    • There were 2 patients with neurological symptoms and discordant CSF-plasma HIV-1 RNA levels

Design :

Objective :

  • Non inferiority in the proportion of patients with treatment success at W48 (per-protocol and ITT analysis) ; lower limit of the two-sided 90% CI for the difference = -10%, 80% power
  • Treatment failure: virologic failure (2 consecutive HIV-1 RNA > 400 c/mL or 1 value > 400 c/mL and a missing confirmation), treatment modification or discontinuation, withdrawal

Baseline characteristics and patient disposition :

Primary endpoint: Therapeutic success (HIV-1 RNA < 400 c/mL) at W48 :

  • Non inferiority of DRV/r monotherapy not demonstrated

HIV-1 RNA < 50 c/mL at W48 :

Other outcomes at W48 :

  • Virologic failure
    • 3 in the DRV/r monotherapy arm vs none in the triple therapy arm
    • 1 patient with V11I mutation (already present before baseline)
  • Resistance
    • No DRV resistance mutations in the 13 patients with 2 consecutive HIV-1 RNA > 50 c/mL (11 in the monotherapy group and 2 in the triple therapy group)
  • CD4 counts
    • No difference in median increase between groups
  • Adherence
    • Adherence was associated with virologic success
  • Baseline HIV-RNA between 50 and 400 c/mL was associated with subsequent HIV-1 RNA > 50 c/mL
  • 2 patients with neurologic symptoms had HIV-1 RNA > 50 c/mL in the CSF(330 ; 580), while < 50 c/mL in the plasma

Adverse events :

Proportion of patients free of virologic rebound (2 consecutive HIV-1 RNA > 50 c/mL) :