Effectiveness of switching to darunavir/cobicistat in virologically-suppressed HIV-positive patients receiving ritonavir-boosted protease inhibitor-based regimen: the "STORE" Study

OBJECTIVE: This study investigates the effectiveness and tolerability of switching to darunavir/cobicistat (DRV/c)-based antiretroviral regimen (ART) from a ritonavir-boosted protease inhibitor (PI/r)-based regimen in virologically suppressed human immunodeficiency virus (HIV)-positive patients. DRV trough values were also investigated. SETTING: Prospective, multicenter, single-country, non-interventional, cohort study. METHODS: This study included patients on a PI/r-based ART for at least twelve months having plasma HIV-1 RNA <50 copies/mL for at least six months. Primary endpoint: HIV-1 RNA <50 copies/mL at 48 ± 6 weeks from baseline. A secondary analysis was performed using the time to loss of virological response (TLOVR) algorithm. Biochemical parameters including DRV trough samples were collected as per clinical practice and measured using high-performance liquid chromatography. RESULTS: Of 336 patients enrolled, 282 completed the study: 70.8% had plasma HIV-1 RNA <50 copies/mL at 48 weeks; using the TLOVR algorithm, 82.7% maintained virological suppression. Virological failure (VF) was observed in 6 patients (1.8%). Adverse event (AE)-related discontinuations were 4.5%. After 48 weeks, we found a significant improvement in both triglycerides (median, 130.0 mg/dL to 113.5 mg/dL, p=0.0254) and HDL cholesterol (48 to 49 mg/dL, p<0.0001) but no change in other biomarkers. DRV trough concentrations in 56 subjects showed a median value of 2862.5 (1469.5-4439.0) ng/mL, higher in females than in males (4221 ng/mL vs. 2634 ng/mL, p=0.046). CONCLUSIONS: In stable HIV-1 positive virologically suppressed patients, the switch to DRV/c-based ART was beneficial in terms of low rates of VF and AEs due to its high tolerability and improvement in triglycerides.