Gilead Sciences Inc. announced today it initiated a Phase II study of a new four-in-one—or “Quad”—HIV treatment. The Quad pill includes Gilead’s experimental integrase inhibitor called elvitegravir, an experimental boosting agent called GS 9350 and the approved drugs Viread (tenofovir) and Emtriva (emtricitabine).

The study will enroll 75 HIV-positive people who’ve never taken antiretroviral therapy before and will randomize them to take either the Quad pill or Atripla (efavirenz, tenofovir and emtricitabine). The 48-week trial will determine both the efficacy and the safety of the Quad pill after 24 and 48 weeks of treatment.

The study is not so much to evaluate the efficacy and safety of elvitegravir—which has already successfully completed a Phase II study and is now in two large Phase III studies—as much as to test the new blood level boosting agent GS 9350, which is being examined as an alternative for low-dose Norvir (ritonavir).