A Study Comparing the Efficacy and Safety of Once-Daily Fuzeon (Enfuvirtide) Dosing Versus the Currently Recommended Twice-Daily Dosing in Human Immunodeficiency Virus-Type 1 (HIV-1) Infected Patients

Inclusion Criteria: * HIV-1 infected adults or adolescents \>=16 years of age; * HIV-1 RNA \>=5000 copies/mL; * prior experience or documented resistance to each of the 3 currently available classes of ARV drugs (nucleoside reverse transcriptase inhibitors, non-nucleoside reverse transcriptase inhibitors, and protease inhibitors). Exclusion Criteria: * history of prior use of Fuzeon or T-1249; * female patients who are pregnant or breastfeeding, or who plan to become pregnant during the study; * current severe illness; * currently taking drugs affecting the immune system, HIV vaccine, or investigational agents for any conditions other than HIV/AIDS.