Drug ‘Cocktails’ May Rid Body of AIDS, Researcher Speculates

WASHINGTON — A leading AIDS researcher on Wednesday raised the provocative notion that powerful drug combinations could eradicate the AIDS virus from the body after three years.

Dr. David Ho, the highly respected director of the Aaron Diamond AIDS Research Center in New York, said a mathematical model developed by one of his collaborators projected the three-year period for eliminating the virus from an infected individual receiving a successful drug-combination treatment.

Ho spoke at the fourth Conference on Retroviruses and Opportunistic Infections, a major gathering devoted to combating AIDS that convened here Wednesday. He predicted that it would take three years for the AIDS virus to “decay,” or burn out, and for new, uninfected cells to replace those that had been destroyed.

“Can HIV be eradicated from the body? The answer is clearly: We don’t know,” Ho told reporters. “Has HIV been eradicated from any of our patients? The answer is: Unequivocally, no. No patient has yet been cured.”

Nevertheless, only four or five years ago researchers were despondent over the lack of effective antiviral drugs available to attack the underlying AIDS infection.

But recent advances have brought a new generation of potent drugs--protease inhibitors--which, when used in conjunction with older therapies, have cemented many scientists’ belief that eventually AIDS will be a controllable disease.

Most scientists now believe that drug “cocktails” are the most effective approach to both halt the replication of the virus and to prevent the development of viral strains that are resistant to any one of the drugs.

“What we’re talking about now is a scientific experiment to suppress replication long enough and completely enough to allow those cells that harbor the virus to be replaced by uninfected cells,” said Dr. Robert T. Schooley, head of infectious diseases at the University of Colorado Health Sciences Center.

The idea is to keep the therapy going until the virus appears to be eliminated in all the locations in the body where it is known to live and replicate, and then stop the drugs to see if the virus rebounds. Ho described studies he is conducting with small numbers of AIDS patients and said that after 18 months of treatment, they have no detectable levels of virus in their blood, semen or in certain lymph tissues in the gastrointestinal system.

This does not necessarily mean that the virus is gone, only that it is undetectable using the most sophisticated technology available to test for its presence.

Ho cautioned that there may be unknown sites where the virus continues to hide.