Government Panel Urges Risky Baboon Transplant for AIDS Patient
Jul. 14, 1995
BETHESDA, Md. (AP) _ At the tearful behest of an AIDS patient's mother and sisters, government advisers recommended Friday that the man be allowed to get a bone marrow transplant from a baboon _ even though they fear it will kill him.
``This is wonderful,'' said Kim Getty, as she raced to telephone the news to her brother Jeff at his San Francisco home.
Scientific advisers to the Food and Drug Administration weren't so optimistic. They warned that the experiment not only will likely kill Getty but must be carefully controlled to ensure that diseases the baboons carry don't spread to humans.
``This probably will hasten his death, not prevent it,'' said Dr. Hugh Auchincloss Jr. of Massachusetts General Hospital.
But if Getty, who is 38, accepts the risks and the doctors follow strict precautions, the panel said, the operation should go forward to prove whether baboons, who don't get AIDS, hold a key to fighting the fatal disease.
The FDA usually follows advisory committee recommendations. Officials indicated a decision could be made in several weeks.
``This is a unique opportunity to actually study the risks'' of cross-species transplants, or xenotransplantation, said FDA biologics chief Dr. Philip Noguchi.
Baboons do not get HIV-1, the type of AIDS virus most prevalent in the United States. Dr. Suzanne Ildstad of the University of Pittsburgh plans to inject baboon bone marrow into Getty.
AIDS destroys blood cells, particularly immune cells. Bone marrow manufactures new blood cells. The theory is that the transplant could resupply Getty's bloodstream with HIV-resistant blood cells.
It is usually impossible to transplant bone marrow between genetically dissimilar people, much less different species. This experiment was tried once before and failed. Ildstad thinks she will succeed because she has discovered ``facilitating cells'' that appear to prevent the body from destroying transplanted marrow.
She was ready to go in April when the FDA told her federal law required prior government clearance for an experiment that could be dangerous to the patient or the public. Thirty days ago, she filed the proper application.
Getty's family and AIDS activists attacked the FDA Friday for the delay. ``Don't take this hope away from him,'' pleaded his mother, Susan Getty. ``Unless you do something now, he will be dead.''
But the FDA acted properly, gene therapy pioneer Dr. W. French Anderson told fellow panel members. The oversight forced Ildstad to strengthen her trial and increase safety precautions, he said, and since that has happened, the experiment ``should be approved now.''
Of particular concern is whether xenotransplants could spread dangerous animal viruses to humans. After all, AIDS itself is believed to have jumped from certain monkeys into humans, and some flu strains come from pigs.
In fact, the two baboons slated for Getty's marrow donation have five known viruses. They possibly could infect Getty outright or merge with each other or a germ already in his body to form a virulent hybrid.
Nobody knows how likely that is, FDA advisers said. But the panel insisted Ildstad look for healthier baboons, proceeding only if there are none or Getty's condition worsens. Searching scientific baboon colonies will take about two weeks.
Regardless, Getty, 38, and his doctors will be repeatedly tested for disease.
But some panelists' biggest fear is that Getty will die before Ildstad can tell if baboon marrow could possibly manufacture blood cells that work in people.
The reason: The baboon's immune cells will be removed from his marrow before the transplant to prevent graft-vs.-host disease, a leading killer of transplant patients. That is risky because AIDS has killed almost all of Getty's own immune cells _ and Ildstad admits her only proof the transplant will manufacture new ones is from studies of laboratory mice.
Still, Getty's family said the man is an eager guinea pig. ``This is what he really wants to do _ to push the science forward for this disease,'' said sister Jennifer Getty.
If the experiment works, the FDA pledged to move quickly to allow further testing on several more AIDS patients.