New AIDS Therapy Nukes HIV
Radioactive Antibodies Seek and Destroy HIV Infected Cells in Mouse Study
Nov. 7, 2006 - Like guided missiles, radioactive anti-HIV antibodies seek
out and destroy HIV-infected cells.
The new approach to AIDS therapy -- called radioimmunotherapy -- works in
mice, report Ekaterina Dadachova, PhD, of New York's Albert Einstein College of
Medicine, and colleagues.
"Radioimmunotherapy is supposed to be curative," Dadachova tells
WebMD. "Current HIV treatments kill the virus, but it will come back
because it hides in latently infected cells. Our goal is to go after those
cells, so radioimmunotherapy has the potential to cure somebody
Dadachova's colleague, Harris Goldstein, MD, tempers his enthusiasm a bit
more. Goldstein is director of the Einstein/MMC Center for AIDS Research in New
"If we had a nickel for every time HIV was cured we'd all be very
wealthy," Goldstein tells WebMD. "But it is exciting when a new
conceptual approach comes along. What makes this treatment unique is that it is
designed to target HIV infected cells and kill them. This really has the
potential to markedly reduce the viral infection in patients."
What has Dadachova and Goldstein so excited is their finding that the new
AIDS therapy concept works not just in the test tube, but in living
The treatment starts with an antibody that homes in on a piece of HIV
(called gp41) that sticks out of HIV-infected cells. The antibody is attached
to a radioactive isotope. It latches on to cells carrying HIV and irradiates
them. Since the antibody doesn't stick to healthy cells, the treatment doesn't
This may sound like the future, but such treatments already exist. The
FDA-approved drugs Zevalin and Bexxar are radioimmunotherapies that target cancer cells in people with non-Hodgkin's lymphoma.
Recently, Dadachova, Goldstein, and others showed that radioimmunotherapy
could be used to treat infections as well as cancers. In their new study, they
show that the technique can seek out and destroy human HIV infected cells
growing in specially bred mice.
"Many things fail in animals that worked in the test tube,"
Goldstein says. "So the antibodies being able to hunt out and eliminate HIV
infected cells brings this a lot closer to the clinic."
Indeed, the researchers hope to begin human clinical trials within two
It's an innovative, interesting approach, says HIV researcher Carrie Dykes,
PhD, of the University of Rochester, New York. Dykes was not involved in the
"I think it could play out," Dykes tells WebMD. "They have a lot
of animal studies to do before they get into humans. But it would be
interesting to see if it would really work."
Current therapy for HIV -- known as highly active antiretroviral therapy or
HAART -- uses a combination of powerful drugs that keep the AIDS virus from
replicating. When treatment is successful, the virus seems to disappear from