Study AI266073 was a 48-week open-label randomised clinical study in HIV infected patients comparing the efficacy of Atripla to antiretroviral therapy consisting of at least two nucleoside or nucleotide reverse transcriptase inhibitors (NRTIs) with a protease inhibitor or non-nucleoside reverse transcriptase inhibitor; however not a regimen containing all Atripla components (efavirenz, emtricitabine and tenofovir disoproxil fumarate).