Switching to Tenofovir/Emtricitabine from Abacavir/ Lamivudine in HIV-Infected Adults with Raised Cholesterol: Effect on Lipid Profiles

BACKGROUND: The aim of this study was to investigate the effect on fasting lipid parameters of switching to tenofovir disoproxil fumarate (TDF) plus emtricitabine (FTC) from abacavir (ABC) plus lamivudine (3TC; both fixed-dose combinations), while maintaining ritonavir-boosted lopinavir (LPV/r). METHODS: This was an open-label randomized two-arm 12-week controlled study in virologically suppressed HIV-infected patients with elevated cholesterol (≥5.2 mmol/l). Patients stable on ABC/3TC plus LPV/r either continued treatment or switched to TDF/FTC plus LPV/r for 12 weeks. Standard efficacy and safety end points (including fasting lipids) were assessed. RESULTS: In total, 85 subjects were treated (n=42 ABC/FTC and n=43 TDF/3TC). A statistically significant decrease in total cholesterol was observed in the TDF/FTC group: from median (IQR) 6.22 mmol/l (5.91-6.77) at baseline to 5.75 mmol/l (5.04-6.18) at week 12 (median [IQR] change from baseline -0.73 mmol/l [-1.20- -0.18]; P<0.001). No notable change was observed for the ABC/3TC group. The difference between groups at week 12 was -0.82 mmol/l (P<0.001). For TDF/FTC (but not for ABC/3TC), statistically significant reductions (P<0.05) from baseline were observed in total, low-density lipoprotein, high-density lipoprotein (HDL)- and non-HDL cholesterol (at weeks 4 and 12). Statistically significant decreases were observed in median estimated creatinine clearance (Cockcroft-Gault) from baseline to week 12 for patients who switched to TDF/FTC (-5.47 ml/min) versus the ABC/3TC group (-2.15 ml/min; P=0.016 between groups). Virological suppression was maintained in both groups. No new safety issues were identified. CONCLUSIONS: Switching to TDF/FTC from ABC/3TC was associated with rapid improvements in fasting lipid parameters and continued virological control in patients receiving LPV/r as the third component of antiretroviral therapy. The effect of these changes on clinical end points remains unclear and would need to be evaluated in a longer-term study.