 A question that has not been explored is whether subjects with sustained undetectable HIV-1 RNA-levels experiencing antiretroviral-related toxicity can safely switch their current PI to etravirine. This treatment strategy could allow improvements in tolerability and lipid profile and would permit an easy posology 400 mg dissolved in water every 24 hours. We designed a proof-of-concept study to test the efficacy and safety of switching from a Protease Inhibitor PI to etravirine in subjects with viral suppression as an antiretroviral strategy of simplification therapy, based on the high antiviral potency, low toxicity, together with its easy posology in water dissolution. 