Efficacy of protease inhibitor monotherapy vs. triple therapy: meta-analysis of data from 2303 patients in 13 randomized trials

The aim of this analysis was to review the evidence and update a meta-analysis evaluating the efficacy and safety results from randomized controlled trials of ritonavir-boosted protease inhibitor (PI/r) monotherapy.

A PubMed/EMBASE search was conducted to find randomized trials of PI/r monotherapy vs. triple therapy in patients with HIV-1 RNA suppression at baseline (<50 HIV-1 RNA copies/mL). Rates of virological suppression were analysed using switch-equals-failure and intensification-included endpoints [intent-to-treat (ITT)]. The rate of treatment-emergent resistance mutations, neurocognitive function endpoints, and cerebrospinal fluid (CSF) HIV-1 RNA were also analysed by treatment arm.

There were 2303 patients from 13 different randomized clinical trials of darunavir/r monotherapy (n = 784: MONET, MONOI, Monarch and PROTEA), lopinavir/r monotherapy (n = 829: OK pilot, OK-04, KalMo, KALESOLO, KRETA, MOST and DREAM), atazanavir/r monotherapy (n = 103: MODAT), or all three (n = 587: PIVOT). HIV-1 RNA plasma suppression was lower in the PI/r monotherapy arm compared with the triple therapy arm in the switch-equals-failure analysis [difference -8.3%; 95% confidence interval (CI) -11.9 to -4.8%], but not when intensification was included (difference 0.5%; 95% CI -2.5 to 3.6%). Rates of resistance mutations were similar between arms, as was overall neurocognitive function.

PI/r monotherapy showed a higher risk of plasma HIV-1 RNA elevations. However, there was no increased risk of treatment-emergent drug resistance, neurocognitive endpoints did not differ, and HIV-1 RNA suppression rates after intensification were similar between PI/r monotherapy and triple therapy.