Emtricitabine/Rilpivirine/Tenofovir Disoproxil Fumarate Single-Tablet Regimen: A Review of Its Use in HIV Infection

The nucleos(t)ide reverse transcriptase inhibitors, emtricitabine and tenofovir disoproxil fumarate (tenofovir DF), and the non-nucleoside reverse transcriptase inhibitor, rilpivirine, are now available as a fixed-dose single-tablet regimen (emtricitabine/rilpivirine/tenofovir DF; Complera®, Eviplera®) for the treatment of adults infected with HIV-1. In treatment-naïve adults, once-daily emtricitabine/rilpivirine/tenofovir DF was noninferior to once-daily emtricitabine/efavirenz/tenofovir DF with regard to establishing virological suppression over 96 weeks of therapy in a randomized, open-label, phase IIIb study (STaR). These data confirmed the findings of a pooled subset analysis of two earlier 96-week, double-blind, phase III trials (ECHO and THRIVE) in which treatment-naïve adults received either rilpivirine or efavirenz in combination with emtricitabine/tenofovir DF. However, the virological benefit of emtricitabine/rilpivirine/tenofovir DF in this setting appeared limited in patients with low CD4+ cell counts or high viral loads at baseline. In 48-week phase IIIb (SPIRIT) and IIb (Study 111) trials in treatment-experienced patients already virologically suppressed with a single- or multiple-tablet antiretroviral regimen and without prior virological failure, switching to once-daily emtricitabine/rilpivirine/tenofovir DF maintained virological suppression and was noninferior to remaining on a more complex multiple-tablet regimen in this regard. Emtricitabine/rilpivirine/tenofovir DF is generally well tolerated and appears to have a more favourable tolerability profile than emtricitabine/efavirenz/tenofovir DF. Thus, emtricitabine/rilpivirine/tenofovir DF is a welcome addition to the other single-tablet regimens currently available for the treatment of HIV-1 infection, providing a convenient and effective option for some adults who are treatment-naïve, as well as those who are already virologically suppressed on their current treatment regimen and wish to switch because of intolerance or to simplify their regimen.