A Randomized, Open-label Study Evaluating the Antiviral Activity and Safety of 3 Month Fuzeon Induction With an Optimized Background Antiretroviral Regimen Versus OB Alone, in Fuzeon-naive HIV-1 Infected Patients With Virological Failure.

This 2 arm study will assess the efficacy and safety of a new regimen of Fuzeon \+ optimized background antiretroviral treatment, in Fuzeon-naive HIV-1 infected patients with virological failure. Eligible patients will be randomized to recei ve either new optimized treatment alone, or optimized treatment + Fuzeon 90mg s. c. twice daily, to determine the effect of 3 month induction with Fuzeon.It will be possible for a patient to receive several additional 3 month periods with F uzeon, in the case of new virological failure. The anticipated time on study tre atment is 3-12 months, and the target sample size is <100 individuals.