Purpose of review: The present review focuses on recent data about boosted protease inhibitor monotherapy for maintenance of HIV virological suppression.
Recent findings: Until recently most of the trials of boosted protease inhibitor monotherapy have studied lopinavir/ritonavir monotherapy. These trials showed a slightly inferior efficacy of lopinavir/ritonavir monotherapy than that of lopinavir/ritonavir and two nucleosides. Two clinical trials [Monotherapy in Europe with TMC114 (MONET) and Monotherapy inhibitor protease (MONOI)] have shown that darunavir/ritonavir monotherapy has also a slightly lower efficacy for maintenance of virological suppression than darunavir/ritonavir with two nucleosides. The risk of resistance development is minimal and patients who fail this strategy can be re-suppressed again by adding nucleosides or switching to a triple therapy regimen without having lost therapeutic options. MONOI has also shown limb fat recovery in patients receiving darunavir/ritonavir monotherapy and good penetration of darunavir in the seminal fluid. There are still conflicting views about the ability of boosted protease inhibitor to protect the central nervous system from HIV replication. There are no randomized clinical trials showing a higher risk of discordant HIV replication in the cerebrospinal fluid in patients exposed to monotherapy. There are insufficient data of monotherapy with atazanavir/ritonavir.
Summary: There currently is no consensus about the role of boosted protease inhibitor monotherapy for the treatment of HIV infection. It is clear that suppression can be maintained in a large proportion of patients without exposing patients to a substantial risk of resistance development, but the precise role of this strategy is still undefined.