This study will examine the safety and effectiveness of daclizumab (also called Zenapax or
anti-CD25) in reducing viral replication in patients with HIV infection. Although HAART, an
intensive anti-HIV treatment regimen, can suppress HIV in blood below the limit of detection,
it cannot completely eradicate the virus. This study will focus on the effectiveness of
daclizumab in further reducing viral replication in patients with low viral counts. The Food
and Drug Administration approved daclizumab in 1997 for preventing kidney transplant
rejection, and it has also been studied in people with an eye infection called uveitis. The
drug works by binding to a protein on T cells (white blood cells of the immune system) called
CD25. This prevents another protein, called interleukin-2 (IL-2), from binding to this site,
thus preventing a series of events that normally results in inflammation.
Patients between 18 and 65 years of age with HIV infection who have stable HIV levels at less
than 30,000 copies/mL of blood and CD4 T cell counts higher than 400 cells/cmm may be
eligible for this study. Patients who have taken drugs that affect the immune system, such as
IL-2 and interferon, in the past 5 years may not participate. Candidates are screened with a
comprehensive medical examination, including physical examination and laboratory studies.
X-rays, consultations, and biopsies are done only if medically indicated.
Participants will undergo the following tests and procedures:
- Daclizumab therapy: Patients receive daclizumab as a 25-minute infusion through an
intravenous catheter (plastic tube placed in a vein) at the NIH Clinical Center
outpatient clinic. A total of three doses of drug are given. The first dose is given on
study day 1, the second dose is given 2 weeks later, and the third dose is given 4 weeks
later. Patients are observed for at least 1 hour after each infusion before being
discharged from the clinic.
- Follow-up visits: Patients return to the outpatient clinic every 2 weeks while they are
on medication and then every month until 3 months after the final dose to evaluate their
infection status, response to therapy, and medication side effects. The visits include a
physical examination, blood draws, and possibly x-rays, if medically indicated.
- Apheresis: Patients undergo apheresis, a procedure for collecting large amounts of white
blood cells, three times during the study - once before starting daclizumab therapy, 4
weeks after beginning therapy, and 12 weeks after beginning therapy. For apheresis,
blood is removed through a needle in the vein of one arm and spun in a machine that
separates it into its components. The white blood cells and plasma are removed, and the
red cells and platelets are re-infused either through the same needle or through a
needle in a vein in the other arm.
Phase:
Phase 1
Details
Lead Sponsor:
National Institute of Allergy and Infectious Diseases (NIAID)