Determinants of use of the fixed dose combination emtricitabine/rilpivirine/tenofovir (Eviplera) in HIV-infected persons receiving care in Italy

INTRODUCTION: Emtricitabine/rilpivirine/tenofovir (EVP) is a fixed-dose combination of antiretrovirals (ARV) approved by the European Medicines Agency in November 2011 and introduced in Italy in February 2013. It is a once-a-day single tablet and is licensed in Europe for use only in ARV-naïve patients with a viral load (VL) ≤100,000 copies/mL. OBJECTIVE: To identify factors that may be associated with the use of EVP as first-line regimen in HIV-infected individuals starting cART from ARV-naïve in Italy. METHODS: Clinical sites in ICONA Foundation Study in which ≥1 person had started EVP were selected for this analysis. From these we included all patients who started an EVP-based cART regimen as well as those starting other cART regimens after the date of introduction of EVP at the site (after February 2013 in any case) and with a VL ≤100,000 copies/mL from ARV-naïve. Characteristics at the time of starting cART were compared using chi-square test and unadjusted and adjusted logistic regression analysis. Factors investigated included: gender, mode of HIV transmission, time from HIV diagnosis, CD4 count, nation of birth, AIDS, HCV-status, age, CD8 count, VL, diabetes, smoking, total and HDL cholesterol, eGFR, blood glucose, level of education and employment and site location. Factors showing unadjusted associations with a p-value of 10% or smaller, were retained in the multivariable model. RESULTS: We identified 183 patients starting EVP and 173 starting the control regimen from 23 sites. The number of patients starting EVP included at each site ranged from 1 to 12 and the number of those starting the control regimen was similar. The most frequently used drugs in the concurrent group were: TDF (75%), FTC (74%), DRV (39%), ATV/r (26%), LPV/r (9%), EFV (13%) and RAL (14%). In univariable analysis, there were differences in median CD4 count (390 cells/mm(3) in EVP versus 348 in controls, p=0.002), time from HIV diagnosis to starting cART (11 versus 3 months, p=0.001) and prevalence of students (6% versus 3%, p=0.07). No differences were observed for all other factors examined. The table shows estimates of the odds ratios (OR) for factors included in the multivariable model. CONCLUSIONS: CD4 count was higher in EVP-treated patients compared to controls. Guidelines suggest avoiding initiation of EVP in presence of high VL, possibly explaining this residual difference in CD4. There was also a tendency to prescribe EVP to people with perceived lower adherence or hesitant to start or perhaps with a slow progressing disease.