Efficacy and Safety Study of Darunavir for the Treatment of HIV/AIDS

The aim of this pilot study is to assess the feasibility, efficacy and safety of Darunavir/ritonavir 800/100 mg once daily (DRV/r) monotherapy as a switch-maintenance strategy for patients receiving second-line ART at Yaoundé Central Hospital in Cameroon. HIV-infected adults receiving second-line antiretroviral therapy (ART) for ≥3 months with 2 nucleos(t)ide reverse transcriptase inhibitors (NRTIs) plus either lopinavir/ritonavir (LPV/r) or atazanavir/ritonavir (ATV/r) will undergo plasma HIV-1 RNA ("viral") load testing. Those with a viral load below 50 copies/ml (\<50 cps/ml) will undergo a repeat test ideally 4-6 weeks later (allowed up to 12 weeks); if the viral load is confirmed as \<50 cps/ml the patient will be invited to join the randomised phase of the study. Patients (n=150) will be randomised 1:2 to either continue the current triple ART regimen (n=50) or switch to DRV/r monotherapy (n=100). The primary end-point will be viral load suppression \<400 cps/ml at week 24; secondary end-points will be viral load suppression \<50 cps/ml at week 12 and week 24, safety, tolerability, and emergence of protease inhibitor (PI) drug-resistance. Patients will continue observational follow-up depending on the treatment arm they are randomized to. After week 48, patients will return to local standard of care. Pharmacokinetics (PK) and pharmacogenomics sub-study to correlate plasma concentrations of DRV to outcomes, HIV-1 drug resistance testing sub study to detect mutants archived at the time of first-line ART failure and measuring HIV DNA load will be performed, as well as a cost-effectiveness analysis will test the hypothesis that savings can be achieved by switching to DRV/r monotherapy without affecting quality of care. The primary virological objective is to evaluate efficacy in terms of the percentage of subjects who have plasma HIV-1 RNA levels \<400 cps/ml after 24 weeks of follow-up following a switch to DRV/r monotherapy versus continuing triple therapy conta