This is an open-label, randomized and multi-center study to compare the efficacy and safety of continued enfuvirtide (Fuzeon) plus (+) OB therapy versus OB alone in participants with HIV-1 infection. Participants will receive an initial 28 week induction treatment with enfuvirtide + OB. After 28 weeks participants with a plasma viral load less than or equal to (</=) 400 copies/milliliter (mL) at Week 16 and less than (<) 50 copies/mL at Week 24 will be randomized in the ratio 1:1 to receive either enfuvirtide + OB or OB alone for another 24 weeks (up to Week 52).