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.