A Pilot Study of Abacavir/Lamivudine and Raltegravir in Antiretroviral-Naive HIV-1-Infected Patients: 48-Week Results of the SHIELD Trial

Purpose: To evaluate raltegravir plus abacavir/lamivudine in antiretroviral-naive, HIV-1-infected patients. Methods: SHIELD is an ongoing 96-week pilot study of abacavir/lamivudine 600 mg/300 mg once daily with raltegravir 400 mg twice daily among HLA-B*5701-negative adults with screening viral load (VL) >1,000 copies/mL. HBsAg+ patients were excluded, as were patients with key mutation(s) to any study drug. Virologic failure (VF) was defined as either VL >400 copies/mL at week 24 or confirmed virologic rebound. Results: Thirty-five patients enrolled (mean age 38.7 years). Most were white males, but 26% self-identified as Hispanic/Latino. At baseline, 34% had VL >= 100,000 copies/mL (median, 4.8 log(10) copies/mL) and 20% had CD4 cell counts <200 cells/mm(3) (median, 301). One patient discontinued due to adverse events (AEs); one patient experienced VF. At week 48, 91% (32/35) had VL <50 and <400 copies/mL by missing/discontinuation equals failure analysis. Median CD4 cell count change from baseline was +247 cells/mm(3). Five patients (14%) had treatment-related grade 2-4 AEs; no treatment-related serious AEs were reported. Over 48 weeks, median fasting lipids increased for total (+17%), LDL (+9%), and HDL (+6%) cholesterol but remained stable for triglycerides (-1%) and total:HDL cholesterol ratio (0%). Conclusions: In this pilot study, abacavir/lamivudine plus raltegravir was effective and generally well-tolerated over 48 weeks with modest changes in fasting lipids.