The study was terminated due to hepatoxicity of compound

The purpose of this study is to evaluate the safety and efficacy of the CCR5 antagonist GW873140 or placebo in combination with an optimized background regimen in treatment-experienced HIV-infected subjects with R5/X4-tropic virus

Inclusion criteria:

• HIV-infected.
• Screening viral load at least 5000copies/mL.
• R5/X4-tropic virus at screening.
• Total prior antiretroviral experience of at least 3 months.
• Documented resistance to at least one drug in each of the following classes: nucleoside reverse transcriptase inhibitors (NRTI), non-nucleoside reverse transcriptase inhibitors (NNRTI), and protease inhibitors (PI), stable antiretroviral regimen (or no antiretroviral treatment) for at least 4 weeks before screening.
• Able to receive a ritonavir-boosted protease inhibitor during treatment studies.
• Women of childbearing potential must use specific forms of contraception.

Exclusion criteria:

• Acute laboratory abnormalities.
• History of pancreatitis or hepatitis, hepatitis B or hepatitis C coinfection, or any chronic liver disease. Screening liver function tests will be used to determine eligibility.
• R5-tropic only.
• X4-tropic only.
• non-phenotypeable virus at screening.
• Changes to antiretroviral therapy from 4 weeks prior to screening until Day 1 of treatment study.
• Pregnancy or breastfeeding women.
• Recent participation in an experimental drug trial.
• Prior use of a CCR5 or CXCR4 antagonist.
• Significant ECG abnormalities or significant history of active pancreatitis, hepatitis, opportunistic infections, malabsorption disorders, cancer, or severe illness.
• Current use of certain medications may exclude participation in this study.
• Additional qualifying criteria and laboratory test requirements to be assessed by study physician.