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 completely."
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 York.
"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 animals.
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 affect them.
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 years.
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 Dadachova/Goldstein study.
"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."