Induction With Abacavir/Lamivudine/Zidovudine Plus Efavirenz for 48 Weeks Followed by 48-Week Maintenance With Abacavir/Lamivudine/Zidovudine Alone in Antiretroviral-Naive HIV-1-Infected Patients

Background: The ESS40013 study tested 4-drug induction followed by 3-drug maintenance as initial antiretroviral therapy (ART) to reduce HIV RNA rapidly and then to simplify to an effective yet more convenient and tolerable regimen. Methods: Four hundred forty-eight antiretroviral-naive adults were treated with abacavir/lamivudine/zidovudine (ABC/3TC/ZDV) and efavirenz (EFV) for the 48-week induction phase. Two hundred eighty-two patients were randomized in a 1:1 ratio to continue ABC/3TC/ZDV + EFV or to simplify to ABC/3TC/ZDV for the 48-week maintenance phase. Results: The baseline median HIV RNA level and CD4 cell count were 5.08 logic copies/mL (56% ≥ 100,000 copies/mL) and 210 cells/mm 3 (48%