Edurant is indicated in combination with other antiretrovirals for treatment-naïve patients with a viral load of 100 000 HIV-1 RNA copies/ml or less. Eviplera, the fixed-dose once-daily combination tablet (rilpivirine, emtricitabine and tenofovir disoproxil), is licensed for the same indication but as monotherapy.
PHARMACOLOGY
Rilpivirine is a non-nucleoside reverse transcriptase inhibitor (NNRTI) of HIV-1. It does not affect human cellular DNA polymerases alpha, beta or gamma. Like other second-generation diarylpyrimidine NNRTIs, it has a higher potency, longer half-life and reduced side-effect profile compared with older NNRTIs.1,2
CLINICAL STUDIES
The efficacy and safety of rilpivirine in triple combination therapy was assessed in 2 randomised, double-blind, phase 3 non-inferiority trials using efavirenz as the comparator. In addition to rilpivirine (25mg) or efavirenz (600mg) once daily, patients enrolled in THRIVE (n=678) received tenofovir disoproxil plus emtricitabine, zidovudine plus lamivudine, or abacavir plus lamivudine; participants in ECHO (n=690) all received tenofovir disoproxil plus emtricitabine. The primary endpoint was virologic response, defined as a viral load of less than 50 HIV-1 RNA copies/ml.3,4
Response rates after 48 weeks were comparable for rilpivirine and efavirenz in both THRIVE (86% vs 82%) and ECHO (83% vs 83%), with rilpivirine meeting the criteria for non-inferiority in both cases. Rates of virologic failure were higher with rilpivirine than efavirenz (THRIVE: 7% vs 5%; ECHO: 13% vs 6%). However, there were fewer Grade 2–4 treatment-related adverse events with rilpivirine than efavirenz (16% vs 31% in both studies) and fewer discontinuations due to adverse events (THRIVE: 4% vs 7%; ECHO: 2% vs 8%).3,4
REFERENCES
1. Edurant Summary of Product Characteristics, November 2011.
2. Eviplera Summary of Product Characteristics, November 2011.
3. Cohen CJ et al. Lancet 2011;378:229-37.
4. Molina JM et al. Lancet 2011;378:238-46.
