An Old New Drug for AIDS

By Christine Gorman

Thalidomide has long been synonymous with tragedy. In the early 1960s, thousands of European women who took the sedative during pregnancy gave birth to children with no arms or legs, and only the vigilance of the Food and Drug Administration prevented a similar disaster in the U.S. But the old drug that once brought despair may one day generate hope for the victims of a modern plague. In an experiment that began in 1992, researchers at Rockefeller University are testing the possibility that thalidomide can fight the ravages of AIDS.

Encouraged by laboratory results suggesting that the drug could suppress the AIDS virus (HIV) in cells grown outside the body, a team of scientists led by immunologist Gilla Kaplan gave thalidomide to a dozen patients in New York City and Thailand. After four to six weeks of therapy, some of them had gained between 10 and 30 lbs. and their fevers had disappeared.

No one believes a cure is at hand, but researchers hope thalidomide can slow the progress of the disease and buy precious time for patients. In the original test-tube trials, reported last week in the Proceedings of the National Academy of Sciences, the drug appeared to prevent some, but not all, HIV-infected cells from producing any new copies of the virus. Thalidomide apparently accomplished this feat by inhibiting a naturally occurring substance called tumor necrosis factor (TNF). Its purpose in the body is to fight cancer and infections, and a side effect of its activity is severe weight loss. In people who are infected with HIV, for some unknown reason, TNF also promotes production of the virus. "We thought that if we could inhibit TNF, then maybe we could decrease some of the clinical symptoms of AIDS," Kaplan says.

Despite the early positive signs, Kaplan does not yet know whether thalidomide has decreased the amount of virus in her patients. Says Dr. Anthony Fauci, head of the National Institute of Allergy and Infectious Diseases: "Certainly this is encouraging enough to pursue other studies with larger numbers of people to see if the effect holds up." Already, the Rockefeller group has launched a second study of about 40 people. Unfortunately, the AIDS virus has a habit of evading most of the roadblocks scientists try to put in its way.