TRIZAL study: Switching from successful HAART to Trizivir™ (abacavir-lamivudine-zidovudine combination tablet): 48 weeks efficacy, safety and adherence results

Abstract

Objective. To assess the antiviral efficacy, safety, and adherence in subjects who switched to Trizivir™ following long-term HIV-1 RNA suppression. Study design. A randomized, open-label, multicentre, 48-week comparative study in subjects who have received two nucleoside reverse transcriptase inhibitors plus a protease inhibitor or an nonnucleoside reverse transcriptase inhibitor or three nucleoside reverse transcriptase inhibitors for at least 6 months, with a history of undetectable plasma HIV-1 RNA since initiation of therapy and plasma viral load of < 50 HIV-1 RNA copies/mL at screening. Methods. Subjects were randomized 1:1 to continue their current treatment or to switch to a simplified treatment with Trizivir™ administered twice daily. Assessments included plasma HIV-1 RNA, lymphocyte counts, clinical laboratory evaluations, adverse events, and adherence to treatment (obtained via subject self-report). Treatment failure was defined as a plasma viral load of ≥ 400 HIV-1 RNA copies/mL on two consecutive occasions or premature discontinuation of randomized treatment. Results. At week 48, the proportion of treatment failures in Trizivir™ arm (23/106, 22%) was noninferior to that observed in continued arm (23/103, 22%) with a treatment difference stratified by prior ART of 1.2% [-10.1; 12.5]. Incidence of adverse events was similar in both treatment groups. The incidence of possible hypersensitivity reaction in the Trizivir™ arm was 10%. Significant reductions in cholesterol and triglyceride plasma levels were observed in the Trizivir™ arm (P < 0.001 and P = 0.006, respectively). Conclucion. Switching to Trizivir™ offers a potent and simplified regimen with equivalent efficacy and significant improvement in lipid abnormalities compared to continued triple therapy.