A 48-Weeks National Multicenter Randomized Open Clinical Trial Evaluating Tolerance and Efficacy of a Treatment Simplification by Lopinavir/Ritonavir Versus Continuation of Current Treatment in HIV-Infected Patients With a Viral Load Inferior to 50 Copies/mL Since 6 Months At Least

Highly active antiretroviral therapy (HAART) has made a significant impact on the natural history of HIV-1 infection, but toxicities and complexities of therapy limit long-term efficacy, and make simpler yet effective HAART regimens highly desirable. Previous attempts to 'de-intensify' protease inhibitor (PI)-based therapy by discontinuing reverse transcriptase inhibitors (RTI) after achieving viral suppression met with failure, probably because plasma levels of most individually administered PI are too low to inhibit viral replication consistently.

Low-dose ritonavir substantially enhances lopinavir plasma levels, and lopinavir/ritonavir (LPV/r) is effective as part of a combination therapy in both naive and PI-experienced patients. Furthermore, lopinavir is known to have a high genetic barrier to selection of resistance. LPV/r monotherapy could thus have the right combination of potency, favorable pharmacokinetics, and high genetic barrier needed to suppress viral replication and prevent the selection of lopinavir resistance. Preliminary results with "maintenance"LPV/r monotherapy show interesting results but data from randomized studies are needed.