The First Failure Study

Inclusion Criteria: * HIV-1 infected males or females * over 18 years of age * signed informed consent * currently receiving a stable antiretroviral regimen comprising of: * two or more licensed NRTIs * one licensed NNRTI or boosted protease inhibitor * no previous protease inhibitor resistance documented on HIV-1 genotypic resistance testing * failure of current antiretroviral regimen due to: * toxicity, intolerance or virological failure if receiving an NNRTI containing regimen at screening * toxicity or intolerance if receiving a boosted-protease inhibitor regimen at screening (with plasma HIV RNA \< 400 copies/mL at screening) * willing to modify antiretroviral therapy, in accordance with the randomisation assignment * no previous exposure to etravirine * subjects in good health upon medical history, physical exam, and laboratory testing in the opinion of the investigator * have no serologic evidence of active HBV infection evidenced by negative hepatitis B surface antigen * female subjects who are heterosexually active and of childbearing potential (i.e., not surgically sterile or at least two years post menopausal) must practice contraception as follows from screening through completion of the study: * barrier contraceptives (condom, diaphragm with spermicide) * IUD or Depo PLUS a barrier contraceptive * female subjects of childbearing potential must have a negative pregnancy test. Exclusion Criteria: * current alcohol abuse or drug dependence * pregnancy * active opportunistic infection or significant co-morbidities * current prohibited concomitant medication * a likelihood of diminished response to any of the study treatment arms, in the opinion of the investigator, based on HIV genotypic resistance testing