Lopinavir/ritonavir monotherapy versus current treatment continuation for maintenance therapy of HIV-1 infection: the KALESOLO trial

We evaluated a monotherapy maintenance regimen with lopinavir/ritonavir versus continuing current combined antiretroviral treatment (cART) in HIV patients with suppressed plasma HIV-1 RNA. This was an open-label, non-inferiority, multicentre trial in 23 sites in France. Adults were randomized if they had no history of virological failure while receiving a protease inhibitor, maintained HIV-1 RNA < 50 copies/mL for at least 6 months and did not change cART during the last 3 months. The primary endpoint was the proportion of patients with HIV-1 RNA < 50 copies/mL at Week 48 (non-inferiority margin set at -12%) with missing data and treatment modification considered as failure. The trial has been registered in ClinicalTrials.gov under the identifier NCT00140751. At Week 48, 84% (73/87) of patients in the lopinavir/ritonavir monotherapy group met the primary endpoint compared with 88% (87/99) in the cART group [difference, -4.0%, lower limit of 90% two-sided confidence interval (CI) for difference, -12.4%]. In secondary analysis with success defined as plasma HIV-1 RNA < 400 copies/mL, 87% (76/87) of patients in the lopinavir/ritonavir monotherapy group were virologically suppressed compared with 88% (87/99) in the cART group (difference, -0.5%, lower limit of 90% two-sided CI for difference, -8.5%). If antiretroviral treatment intensification was taken into account, 91% (79/87) of patients in the lopinavir/ritonavir monotherapy group met the primary endpoint compared with 88% (87/99) in the cART group (difference, +2.9%, lower limit of 90% two-sided CI for difference, -4.5%). Failures of lopinavir/ritonavir monotherapy did not show acquired resistance mutations in the protease gene. Lopinavir/ritonavir monotherapy did not achieve non-inferiority versus cART for maintaining plasma HIV-1 RNA < 50 copies/mL. Nevertheless, the incidence of virological failure was low (mostly with HIV-1 RNA < 400 copies/mL) and easily managed by treatment intensification.