The Single-Tablet Regimen ( STaR ) study ( GS-US-@-@ ) is a @-week phase @b study evaluating the safety and efficacy of @ single-tablet regimens , rilpivirine/emtricitabine/tenofovir DF ( RPV/FTC/TDF ) , and efavirenz/emtricitabine/tenofovir DF ( EFV/FTC/TDF ) in treatment-naive HIV-@-infected subjects .