An Open-Label Study to Evaluate the Efficacy and Safety of Amprenavir (141W94) and Abacavir Combination Therapy in Protease Inhibitor Experienced Subjects With HIV-1 Infection Who Are Failing Their Current Antiretroviral Treatment Regimen

This study is being conducted to provide open-label APV to patients in danger of HIV disease progression, as well as those who may benefit beyond the expected outcomes of current anti-retroviral therapies. Despite unapproved status, APV may prove highly efficacious in combatting HIV progression and may help those in need, prior to regulatory approval. Patients are stratified into one of the following treatment options: Non-nucleoside reverse transcriptase inhibitor (NNRTI)-naive: Option 1- APV / ABC / PI / NNRTI / +nucleoside reverse transcriptase inhibitor(s) (NRTI) Option 2- APV / ABC / NNRTI / NRTI(s) NNRTI-Experienced Patients: Option 1- APV / ABC / PI / +NRTI(s) Option 2- APV / ABC / +NRTI(s) To assess clinical efficacy, lab values (i.e., hematology, serum chemistry, plasma HIV-1 viral load determination and CD4+ cell count measurements) are collected at pre-entry and every 12 weeks thereafter.