US
doctors in Philadelphia said they have saved a seven-year-old girl who was
close to dying from leukemia with a pioneering use of an unlikely ally: a
modified form of the HIV virus.
After fighting her disease with chemotherapy for
almost two years and suffering two relapses, the young girl “faced grim
prospects,” doctors at Children’s Hospital of Philadelphia said.
So in February this year they agreed to take her on
in an experimental program that fought fire with fire.
Helped by a genetically altered HIV virus — stripped
of its devastating properties that cause AIDS — doctors turned the girl’s own
immune cells into a superior force able to rout the “aggressive” leukemia.
The treatment of Emily Whitehead was one of the
very first of its kind and cannot yet be considered “a magic bullet,” the
hospital said. But in Emily’s case, it apparently worked completely.
First, millions of the girl’s natural immune system
cells were removed. Then the modified HIV virus was used to carry in a new gene
that would boost the immune cells and help them spot, then attack cancer cells
that had previously been able to sneak in “under the radar,” the hospital said
on its website.
Finally the rebooted immune cells were sent back in
to do their work.
“The researchers have created a guided missile that
locks in on and kills B cells, thereby attacking B-cell leukemia,” the hospital
said.
Pediatric oncologist Stephan Grupp, who cared for
the girl, explained Tuesday that there was never any danger of AIDS during the
process.
“The way we get the new gene into the T cells
(immune cells) is by using a virus. This virus was developed from the HIV
virus, however all of the parts of the HIV virus that can cause disease are
removed,” he said in an email.
“It is impossible to catch HIV or any other infection.
What’s left is the property of the HIV virus that allows it to put new genes
into cells.”
During the treatment, Emily became very ill and
went into the intensive care unit, underlining how risky the procedure can be.
However, drugs that partly block the immune reaction were administered, without
interfering with the anti-leukemia action, and she recovered, the hospital
said.
The result was “complete” and best of all, the
doctors say, the boosted immune shield continues “to remain in the patient’s
body to protect against a recurrence of the cancer.”
“She has no leukemia in her body for any test that
we can do — even the most sensitive tests,” Grupp told ABC television. “We need
to see that the remission goes on for a couple of years before we think about
whether she is cured or not. It is too soon to say.”
Grupp said on the Children’s Hospital of
Philadelphia website that cell therapies might eventually replace the more
costly, painful bone marrow transplant treatment, a standard last-ditch defense
against cancer.
“I’ve been meeting with families to discuss bone
marrow transplant for 20 years,” he said. “In almost every meeting, I say that
bone marrow transplant is very hard and that if we had an alternative for
children at that point in treatment, I would be delighted to put myself out of
business. And for the first time, we’re seeing how that might actually happen.”

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