Long-term (4 years) efficacy of lopinavir/ritonavir monotherapy for maintenance of HIV suppression.

OBJECTIVES Data are scarce on the long-term efficacy of lopinavir/ritonavir monotherapy for the maintenance of HIV suppression. Four years of results of patients randomized to monotherapy in the Only Kaletra (OK) pilot clinical trial are presented. PATIENTS AND METHODS Twenty-one HIV-infected patients with suppressed HIV replication (<50 copies/mL) for at least 6 months and without previous failure while receiving a protease inhibitor-based regimen started lopinavir/ritonavir monotherapy. Follow-up was performed within the OK pilot clinical trial during the first 2 years and according to routine clinical practice during the 3rd and 4th years. RESULTS Fourteen patients (67%) remain on monotherapy and with RNA <50 copies/mL (intention-to-treat analysis, with missing patients scored as failures). Five patients (24%) had virological rebound and all of them were successfully re-suppressed by adding two nucleosides. No major protease inhibitor mutations were found. CONCLUSIONS Our data support the long-term efficacy and safety of lopinavir/ritonavir monotherapy for the maintenance of HIV suppression, a finding that must be confirmed in larger studies.