Simplification to dual-therapy containing lamivudine and darunavir/ritonavir or atazanavir/ritonavir in HIV-infected patients on virologically suppressive antiretroviral therapy

Background: The ritonavir-boosted protease inhibitor (PI/r)-based dual regimens are warranted in order to optimize the combination antiretroviral therapy (cART), prevent the long-term toxicity and reduce the cost of treatments. Methods: We performed an observational, retrospective study of HIV-infected patients on suppressive antiretroviral therapy who switched to a dual regimen containing lamivudine (3TC) plus darunavir/ritonavir (DRV/r) 800/100 mg qd or atazanavir/ritonavir (ATV/r) 300/100 mg qd. Results: As a whole, 122 well-treated patients (mean age, 45.2 years; mean CD4 T + lymphocyte count, 589 cells/mm³; mean duration of current cART, 3.1 years) were enrolled. Current antiretroviral regimen included tenofovir/emtricitabine in 91 subjects, abacavir/lamivudine in 25, lopinavir/r in 41, DRV/r in 38 and ATV/r in 33. Baseline mean estimated glomerular filtration rate (eGFR) was 94.2 mL/min/1.73 m², and proteinuria was detected in 46 subjects (38%). Overall 70 subjects switched to 3TC + DRV/r (group A) and 52 to 3TC + ATV/r (group B). After 12 months, 65 patients (92.8%) in group A and 46 (88.4%) in group B showed HIV RNA <20 copies/mL. A significant and comparable increase in eGFR was observed in group A and B (+3.8 and +3.1 mL/min/1.73 m², respectively), such as a significant decrease in prevalence of proteinuria. A significantly greater increase in total bilirubin concentration was reported in group B than in group A. Conclusion: In our study, simplification to a dual therapy containing 3TC + DRV/r or ATV/r in virologically suppressed patients was effective and showed a good tolerability profile.