Short Communication: Efficacy and Safety of Treatment Simplification to Lopinavir/Ritonavir or Darunavir/Ritonavir Monotherapy: A Randomized Clinical Trial

Antiretroviral treatment simplification strategies based on monotherapy with darunavir/ritonavir (DRV/r) or lopinavir/ritonavir (LPV/r) have not been directly compared in clinical trials. We evaluated the 48-week efficacy and safety of DRV/r versus LPV/r monotherapy as a treatment simplification strategy in a multicenter, randomized open-label study. Maintenance of viral suppression in cerebrospinal fluid (CSF) and semen was also explored. An intention to treat efficacy analysis was performed considering missing equals to failure (ITT:M=F). Virological failure (VF) was defined as a confirmed increase in plasma HIV-1 RNA >50 copies/mL. A total of 75 patients were enrolled: 40 were allocated to DRVr and 33 to LPVr. In the ITT: M=F analysis, 77.5% of patients on DRV/r and 66.6% of patients on LPV/r maintained HIV-1 RNA <50 copies/mL at week 48 (p=.302, treatment difference 10.8% [95% CI,-12.6 to 34.2]). In the DRV/r arm, no patients developed VF and 15.0% discontinued treatment due to adverse events. In the LPV/r arm, 2 (6.1%) patients developed VF and 18.2% discontinued monotherapy due to adverse events. Gastrointestinal disturbances were experienced by 18.2% and 2.5% of patients in the LPV/r and DRV/r arms, respectively (p=.019). Two patients had detectable HIV-1 RNA 50 copies/mL in CSF or semen. Monotherapy with LPV/r or DRV/r seems to be virologically effective in selected HIV-1-infected patients with sustained viral suppression. Differences between both regimens seem driven mainly by the better tolerability profile of DRV/r.