Single-Tablet HIV Regimen Maintains Virologic Suppression, Improves Fasting Lipids

SAN FRANCISCO, CA—Patients with HIV-1 who received a simplified rilpivirine/emtricitabine/tenofovir DF (RPV/FTC/TDF) once-daily single-tablet regimen maintained virologic suppression and maintained fasting lipids at 48 weeks regardless of whether they initiated this regimen at baseline or at Week 24, as presented at IDWeek 2013.

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“Simplifying to RPV/FTC/TDF also led to significant improvement in fasting total cholesterol, LDL, and triglycerides, including significant changes in those NCEP [National Cholesterol Educational Program] categories,” noted Pablo Tebas, MD, of the University of Pennsylvania School of Medicine, Philadelphia, PA.

Noting that simplifying an antiretroviral regimen “can improve quality of life and medication adherence while reducing the risk of HIV virologic failure and long-term drug-related toxicities,” Dr. Tebas and colleagues initiated the SPIRIT study, a Phase 3b, multicenter, randomized, open-label, 48-week study.

This was the first study to evaluate the safety and efficacy of switching from ritonavir-boosted protease inhibitor (PI+RTV) plus two nucleoside reverse transcriptase inhibitors (2NRTIs) based HAART to a simplified regimen of single-tablet regimen (RPV/FTC/TDF) in virologically suppressed patients with HIV-1.

Patients were randomized 2:1 to switch to RPV/FTC/TDF at baseline (n=317) or maintain their current PI+RTV+2NRTI regimen until a delayed switch to RPV/FTC/TDF at Week 24 (n=159). The primary end point was noninferiority (12% margin) of RPV/FTC/TDF to PI+RTV+2NRTI in maintaining plasma HIV-1 RNA <50c/mL (virologic suppression) at Week 24 by FDA snapshot analysis.

Dr. Tebas reported the primary end point was met: virologic suppression for patients taking the simplified regimen was 93.7% vs. 89.9% for the PI+RTV+2NRTI regimen (difference, 3.8%; 95% CI -1.6–9.1). Through Week 48, 89.3% of subjects simplifying to the RPV/FTC/TDF regimen at baseline and 92.1% of subjects who simplified at week 24 maintained virologic suppression.

At Week 24, patients who switched to the RPV/FTC/TDF regimen had significantly greater mean change from baseline in fasting lipids: total cholesterol (-25mg/dL), LDL (-16mg/dL), triglycerides (-54mg/dL), and HDL (-4mg/dL); all P<0.001. Significantly greater percentages of patients also achieved NCEP targets: 84% reduction in cholesterol to <200mg/dL (P<0.001), 45% to an optimal LDL <100mg/dL (P<0.001), 84% to normal triglycerides <150 mg/dL (P<0.001). A total of 17% increased their HDL to ≥60mg/dl (P=0.48).

Swithcing to RPV/FTC/TDF was non-inferior to remaining on PI+RTV+2NRTIs. “Simplifying from a ritonavir-boosted protease inhibitor regimen to RPV/FTC/TDF in HIV-1 RNA suppressed patients may be an effective therapeutic choice for maintaining virologic suppression and improving lipid profiles,” reportd Dr. Tebas.

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