To investigate the relationship between the pharmacokinetics and pharmacodynamics of UK-427,857 and its antiviral effects in patients with human immunodeficiency virus (HIV).

Inclusion Criteria:

Inclusion criteria:

• Male with HIV or surgically sterilized female with HIV showing no symptoms of HIV
• Weight between 50 and 90kg and within the permitted range for their height

Exclusion Criteria:

Exclusion criteria:

• Subjects with a CD4 count less than 250cells/mm3 or HIV viral load of less than 5000 copies/mL
• Subjects with acquired immune deficiency syndrome (AIDS) or a previous AIDS diagnosis
• Subjects whose HIV infection has been diagnosed less than 3 months prior to screening, or for who there is evidence of recent seroconversion
• Subjects who have taken anti-retroviral drugs in the eight weeks prior to the study screening visit