Intermittent vs. Continuous HAART to Treat Chronic HIV Infection

This study will evaluate the effects of intermittent short cycles of HAART (highly active antiretroviral therapy) for treating HIV infection. HAART is a multi-drug regimen that is very effective in suppressing HIV and perhaps slowing or halting progression to AIDS. However, the treatment has significant drawbacks: it cannot completely rid the body of virus; long-term therapy carries a risk of toxicity (harmful side effects); and the regimen is difficult to comply with because many pills and capsules must be taken daily. When patients stop taking HAART, their HIV levels climb again. This study will see if giving HAART in short cycles of 7 days on, 7 days off, can keep viral levels low while maintaining CD4+ T cell counts. HIV-infected people age 18 or older who are receiving HAART and have a viral load of less than 50 copies/ml and a CD4+ T cell count of at least 175 cells/mm3 may be eligible for this study. Candidates will be screened with a medical history and physical examination, blood and urine tests, and possibly a chest X-ray and electrocardiogram. Women of childbearing potential will have a pregnancy test. Participants will be randomly assigned to either continue their current medication regimen or to take HAART in intermittent cycles of 7 days off, 7 days on. Patients will continue treatment for 72 weeks or until viral levels increase or CD4+ T cell counts decline to a level of concern. Upon entering the study, patients will have blood tests to monitor the amount of virus in the blood, CD4+ T cell count, viral resistance to HAART medications, side effects of the drug, and immune response to HIV in the test tube. They will have clinic visits for a history, physical examination and blood draws every month for 12 months. At that time, depending on T cell counts and viral load, the number of visits may be reduced, but never less frequently than every other month. Patients will also undergo leukapheresis-a procedure for collecting quantities of white blood ce