HEALTH ECONOMICS ASSESSMENT OF RILPIVIRINE VS. COMPARATORS AS FIRST-LINE ANTIRETROVIRAL THERAPIES IN HIV-1 PATIENTS WITH A VIRAL LOAD (VL) ≤100,000 COPIES/ML IN FRANCE

OBJECTIVES: In France, rilpivirine is reimbursed for HIV-1-infected treatment-naïve patients with VL≤100,000 copies/mL for whom the use of efavirenz is not appropriate. This analysis aims to compare costs and outcomes of rilpivirine vs. other third antiretroviral (ARVs) agent recommended in France (in addition to two NRTIS).  METHODS: A cohort-based Markov model with four therapy lines and six health states based on CD4+ cell-count ranges was developed based on 1-year cycle and a 5-year time horizon. First-line efficacy data at 48 and 96 weeks was first assumed to be similar across treatments, and subsequently set to statistically significantly different (SSD) values from phase-III trial analyses of patients with VL≤100,000 copies/mL. Costs of first-line treatments were obtained from the French National Formulary. Costs associated with subsequent treatments and CD4+ health states were derived from a French cost-effectiveness analysis. Other clinical inputs, HIV-related mortality rates and utility were derived from international publications. Outcomes and costs were discounted at 4%. Robustness of results was assessed using sensitivity analyses (e.g. using efficacy values no SSD). RESULTS: All phase-III trials (i.e. ECHO/THRIVE, STARTMRK, CASTLE, ARTEMIS, KLEAN, GEMINI, 2NN) demonstrated a non-inferior antiviral efficacy between arms. In patients with VL≤100,000 copies/mL, response rates were available for rilpivirine (1-year: 90,2%; 2-year: 84,0%), ritonavir-boosted (/r) darunavir (1-year: 79,5%; 2-year: 76,1%), lopinavir/r (1-year: 84,5%; 2-year: 75,2%), atazanavir/r (1-year: 82%; 2-year: 75%), fosamprenavir/r (1-year: 67%) and raltegravir (1-year: 93%). CD4+ cell count changes per mm3 were available for atazanavir/r (1-year: +179; 2-year: +243), lopinavir/r (1-year: +194; 2-year: +267), rilpivirine (1-year: +185) and raltegravir (1-year: +180). Rilpivirine was the less expensive option in the cost-minimisation analyses and dominated all treatments in the cost-effectiveness analyses when considering SSD efficacy values. CONCLUSIONS: The analysis provided health economic results for HIV-1-infected treatment-naïve patients with VL≤100,000 copies/mL favoring rilpivirine over all other ARVs analysed.