Patients were randomly assigned ( @:@ ) to receive once-daily oral tablets containing @ mg elvitegravir , @ mg cobicistat , @ mg emtricitabine , and @ mg tenofovir alafenamide ( E/C/F / tenofovir alafenamide ) or @ mg tenofovir disoproxil fumarate ( E/C/F / tenofovir disoproxil fumarate ) with matching placebo .