Comparison of Pharmacy Costs Between HAART Therapies for HIV Infection

Cincinnati—The accepted therapy for HIV infection has been highly active antiretroviral therapy (HAART), which has usually involved combinations of ≥3 distinct therapies such as 2 nucleoside reverse transcriptase inhibitors (NRTIs) and a protease inhibitor (PI), 2 NRTIs and a non-nucleoside reverse transcriptase inhibitor (NNRTI), or other similar combinations. However, a single-tablet regimen (STR) would potentially improve the quality of life for patients by simplifying the dosing routine, increasing long-term adherence, reducing virologic failure (VF), and reducing long-term toxicities, according to researchers.

Complera^® (emtricitabine 200 mg/rilpivirine 25 mg/tenofovir disoproxil fumarate 300 mg) is an STR that combines emtricitabine with rilpivirine and tenofovir DF. A group of investigators conducted a randomized, open-label, international, 48-week study to evaluate the safety, efficacy, and cost of switching from PI+RTV-based HAART to the FTC/RPV/TDF STR regimen in virologically suppressed [HIV-1 RNA (VL) <50 copies/mL] HIV-1 infected subjects.

The results of the study were presented during a poster session at the AMCP meeting. The poster was entitled Comparison of Pharmacy Costs after Switching to Emtricitabine/Rilpivirine/Tenofovir DF (FTC/RPV/TDF) Single-Tablet Regimen (STR) from a Ritonavir-Boosted Protease Inhibitor (PI+RTV) and Two Nucleoside Reverse Transcriptase Inhibitors (NRTIs).

A total of 476 subjects who had been on a stable first or second PI-RTV HAART regimen for ≥6 months without prior NNRTI use were included in the study. Patients were randomized in a 2:1 ratio; the first group (n=317) was assigned to the FTC/RPV/TDF STR regimen for 2 consecutive periods of 24 weeks. The second group (n=159) was assigned to a PI+RTV+2NRTI regimen for the first 24 weeks and the FTC/RPV/TDF STR regimen for the second 24 weeks.

Baseline and disease characteristics of both groups were similar. The primary end point was noninferiority (12% margin) to PI+RTV+2NRTI by FDA snapshot analysis [HIV-1 RNA (VL) <50 copies/mL] at 24 weeks. Secondary end points included safety and tolerability at 24 and 48 weeks; change in CD4 cell count at 24 and 48 weeks; patient-reported outcomes at 24 and 48 weeks; change in fasting lipid parameters at 24 and 48 weeks; and costs of switching to FTC/RPV/TDF STR through 24 weeks. At baseline, FTC/TDF accounted for 80% of subjects’ NRTI antiretrovirals; ATVs were 37% and LTVs accounted for 33% of RTV-boosted PIs.

At week 24, virologic suppression (FDA snapshot analysis) had been detected in 93.7% of the FTC/RPV/TDF STR group and 89.9% of the PI+RTV+2NRTI group; there was nonsuppression in 0.9% of the STR group and 5.0% of the PI+RTV+2NRTI group as well as insufficient data in 5.4% of the STR group and 5.0% of the PI+RTV+2NRTI group.

There were grade 3 or 4 adverse events involving 16 patients (5.0%) in the first group (STR) and 11 patients (6.9%) in the second group (PI+RTV+2NRTI); there were 20 (6.3%) grade 3 or 4 laboratory abnormalities in the first group and 18 (11.3) in the second group. There were fewer participant-reported gastrointestinal symptoms by the HIV Participant Index as well as improvements in fasting lipids, including total cholesterol, low-density lipoprotein, triglycerides, and total cholesterol: high-density lipoprotein ratio.

Patients who switched to FTC/RPV/TDF STR were less likely to report fatigue (P=.002), memory loss (P=.022), headache (P=.003), and depression (P=.001) at week 24 compared with baseline. There was also higher participant-reported satisfaction with the treatment regimen by HIV-TSQ.

The mean wholesale acquisition cost (WAC) per participant in the STR group for 24 weeks of therapy was $10,275; WAC per participant in the PI+RTV+2NRTI group for that period of time was $12,272, which represented a savings of $1997 (16%) per person in the STR group.

This study was supported by Gilead Sciences, Inc.