Substituting abacavir for hyperlipidemia-associated protease inhibitors in HAART regimens improves fasting lipid profiles, maintains virologic suppression, and simplifies treatment

BACKGROUND: Hyperlipidemia secondary to protease inhibitors (PI) may abate by switching to anti-HIV medications without lipid effects. METHOD: An open-label, randomized pilot study compared changes in fasting lipids and HIV-1 RNA in 104 HIV-infected adults with PI-associated hyperlipidemia (fasting serum total cholesterol >200 mg/dL) who were randomized either to a regimen in which their PI was replaced by abacavir 300 mg twice daily (n = 52) or a regimen in which their PI was continued (n = 52) for 28 weeks. All patients had undetectable viral loads (HIV-1 RNA <50 copies/mL) at baseline and were naïve to abacavir and non-nucleoside reverse transcriptase inhibitors. RESULTS: At baseline, the mean total cholesterol was 243 mg/dL, low density lipoprotein (LDL)-cholesterol 149 mg/dL, high density lipoprotein (HDL)-cholesterol 41 mg/dL, and triglycerides 310 mg/dL. Mean CD4+ cell counts were 551 and 531 cells/mm(3 )in the abacavir-switch and PI-continuation arms, respectively. At week 28, the abacavir-switch arm had significantly greater least square mean reduction from baseline in total cholesterol (-42 vs -10 mg/dL, P < 0.001), LDL-cholesterol (-14 vs +5 mg/dL, P = 0.016), and triglycerides (-134 vs -36 mg/dL, P = 0.019) than the PI-continuation arm, with no differences in HDL-cholesterol (+0.2 vs +1.3 mg/dL, P = 0.583). A higher proportion of patients in the abacavir-switch arm had decreases in protocol-defined total cholesterol and triglyceride toxicity grades, whereas a smaller proportion had increases in these toxicity grades. At week 28, an intent-to treat: missing = failure analysis showed that the abacavir-switch and PI-continuation arms did not differ significantly with respect to proportion of patients maintaining HIV-1 RNA <400 or <50 copies/mL or adjusted mean change from baseline in CD4+ cell count. Two possible abacavir-related hypersensitivity reactions were reported. No significant changes in glucose, insulin, insulin resistance, C-peptide, or waist-to-hip ratios were observed in either treatment arm, nor were differences in these parameters noted between treatments. CONCLUSION: In hyperlipidemic, antiretroviral-experienced patients with HIV-1 RNA levels <50 copies/mL and CD4+ cell counts >500 cells/mm(3), substituting abacavir for hyperlipidemia-associated PIs in combination antiretroviral regimens improves lipid profiles and maintains virologic suppression over a 28-week period, and it simplifies treatment

Pharmacokinetics and Short-Term Safety of 873140, a Novel CCR5 Antagonist, in Healthy Adult Subjects

873140 is a novel CCR5 antagonist with potent in vitro anti-human immunodeficiency virus (HIV) activity. This study was a double-blind, randomized, placebo-controlled, single- and repeat-dose escalation investigation of the safety, pharmacokinetics, and food effect of 873140 in 70 adult subjects. During single-dose escalation, three cohorts (each composed of 10 subjects, with 8 subjects receiving the active drug and 2 subjects receiving the placebo [8 active and 2 placebo]) received doses of 50, 200, 400, 800, and 1,200 mg after an overnight fast, or 400 mg plus a standard high-fat breakfast in an alternating panel design. During repeat-dose escalation, four cohorts (each with 8 active and 2 placebo) received doses of 200, 400, 600, or 800 mg every 12 h (BID) for 8 days. Laboratory safety tests, vital signs, and electrocardiograms (ECGs) were performed at regular intervals, and blood samples were obtained for pharmacokinetics. Single and repeat doses of 50 mg to 800 mg were well tolerated, with no serious adverse events and no grade 3 or 4 adverse events. The mild-to-moderate side effects were primarily gastrointestinal and included abdominal cramping, nausea, and diarrhea. No specific trends in laboratory parameters or clinically significant ECG changes were noted. Plasma 873140 concentrations increased rapidly; the median time to maximum concentration of drug in serum was 1.75 to 5 h. The median area under the plasma concentration-time profile (AUC) and the maximum concentration of drug in serum (C(max)) ranged from 127 ng · h/ml and 24 ng/ml at 200 mg BID to 329 ng · h/ml and 100 ng/ml at 800 mg BID, respectively. Food consumption increased the AUC and C(max) by a mean of 1.7- and 2.2-fold, respectively. The pharmacokinetic and safety profile supports the continued investigation of 873140 with HIV-infected subjects