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.