People infected with HIV may have low levels of the virus in their body, even if they are taking HIV medications. This study will evaluate the safety, pharmacokinetics (PK) (which is how the body interacts with drugs), and immune response to BMS-936559, a drug that will be administered by an intravenous (IV) infusion, in HIV-infected people receiving combination antiretroviral therapy (cART) who have viral load levels below the limit of detection.