Dual therapy with ritonavir-boosted protease inhibitor (PI) plus lamivudine versus triple therapy with ritonavir-boosted PI plus two nucleos(t)ide reverse-transcriptase inhibitor in HIV-infected patients with viral suppression.

Abstract

Dual antiretroviral regimens are attractive options to optimize the combination antiretroviral therapy in light of potential toxicities with long-term cumulative exposure to nucleos(t)ide reverse-transcriptase inhibitors (NRTIs). In this retrospective observational study, we included HIV-infected patients on suppressive antiretroviral therapy with plasma viral load (PVL)<200 copies/mL for at least 6 months who were switched to dual regimens containing lamivudine (3TC) (150mg twice daily or 300mg once daily) plus lopinavir/ritonavir (LPV/r) 250/50mg twice daily or darunavir/ritonavir (DRV/r) 800/100mg once daily. Patients maintaining on suppressive triple therapy with DRV/r or LPV/r plus two NRTIs were included for comparisons. The primary endpoint was the proportion of patients with PVL <50 copies/mL after 48 weeks of follow-up. In total, 364 patients were included with 93 (25.5%) switched to dual therapy After 48 weeks of observation, PVL <50 copies/mL was observed in 96.8% and 94.1% of dual-therapy and triple-therapy group, respectively, in per-protocol analysis (difference 2.7%; 95% CI -2.5%-7.9%). Nineteen patients (3 [3.2%] in dual-therapy and 16 [7.6%] in triple-therapy group) developed virologic failure, with none having emergent M184V resistance-associated mutation. A statistically significant increase of cholesterol level (13mg/dL versus 2mg/dL, p=0.003) and high-density lipoprotein (3mg/dL versus -2mg/dL, p=0.019) were observed in dual-therapy than in triple-therapy group. Changes of triglyceride, low-density lipoprotein and glycated hemoglobin levels were similar between the two groups. Dual therapy with DRV/r or LPV/r plus lamivudine demonstrated similar effectiveness in maintaining viral suppression to triple therapy.