This study will evaluate the safety, pharmacokinetics and efficacy of the CCR5 antagonist INCB009471 in HIV-1 infected patients who are antiretroviral therapy naïve, or who are not currently on a HAART regimen and have not received any antiretroviral agents for 3 months prior to the Screening visit. Subjects will receive study medication (INCB009471) admnistered orally or placebo once daily with food for 14 days. Clinical safety laboratories, 12-lead electrocardiograms, physical examinations and virologic assessments, including viral load, viral tropism and CD4+ cell count determinations will be performed at the Screening visit and at regularly scheduled visits throughout the study. A blood sample will also be obtained and stored to potentially determine the genotype of the CCR5 receptor.