Objective
To evaluate virologic response rates of lopinavir/ritonavir (LPV/r) monotherapy as second-line antiretroviral treatment (ART) among adults in resource-limited settings (RLS).
Design
Open-label pilot study of LPV/r monotherapy in participants on first-line non-nucleoside reverse transcriptase inhibitor 3-drug combination ART with plasma HIV-1 RNA 1000–200 000 copies/mL.
Methods
Participants were recruited from 5 sites in Africa and Asia within the AIDS Clinical Trials Group (ACTG) network. All participants received LPV/r 400/100mg twice daily. The primary endpoint was remaining on LPV/r monotherapy without virologic failure (VF) at week 24. Participants with virologic failure were offered addition of emtricitabine and tenofovir (FTC/TDF) to LPV/r.
Results
Mutations associated with drug resistance were encountered in nearly all individuals screened for the study. One hundred and twenty-three participants were enrolled, and 122 completed 24 weeks on study. A high proportion remained on LPV/r monotherapy without VF at 24 weeks (87%). Archived samples with HIV-1 RNA levels < 400 at week 24 (n = 102) underwent ultrasensitive assay. Of these subjects, 62 had levels < 40 copies/mL and 30 had levels 40–200. Fifteen subjects experienced VF, among whom 11 had resistance assessed, and 2 had emergent protease inhibitor mutations. The presence of baseline thymidine analogue mutations and K65R predicted a lower VF rate. Thirteen subjects with VF added FTC/TDF, and 1 subject added FTC/ TDF without VF. At study week 48, 11/14 adding FTC/TDF had HIV-1 RNA levels < 400 copies/mL.
Conclusions
In this pilot study conducted in diverse RLS, LPV/r monotherapy as second-line ART demonstrated promising activity.