Victoria Gray's blood was drawn so that doctors could get to the cause of her illness -- stem cells from her bone marrow that were making deformed red blood cells (AFP Photo) |
Washington (AFP) - In the summer, a mother in Nashville with a seemingly incurable genetic disorder finally found an end to her suffering -- by editing her genome.
Victoria
Gray's recovery from sickle cell disease, which had caused her painful
seizures, came in a year of breakthroughs in one of the hottest areas of
medical research -- gene therapy.
"I
have hoped for a cure since I was about 11," the 34-year-old told AFP in
an email.
"Since
I received the new cells, I have been able to enjoy more time with my family
without worrying about pain or an out-of-the-blue emergency."
Over
several weeks, Gray's blood was drawn so doctors could get to the cause of her
illness -- stem cells from her bone marrow that were making deformed red blood
cells.
The stem
cells were sent to a Scottish laboratory, where their DNA was modified using
Crispr/Cas9 -- pronounced "Crisper" -- a new tool informally known as
molecular "scissors."
The
genetically edited cells were transfused back into Gray's veins and bone
marrow. A month later, she was producing normal blood cells.
Medics warn that caution is necessary but, theoretically, she has been cured.
DNA from
Gray's stem cells was modified at a Scottish laboratory, using Crispr/Cas9 --
pronounced "Crisper" -- a new tool informally known as molecular
"scissors" (AFP
Photo/GERARD JULIEN)
|
Medics warn that caution is necessary but, theoretically, she has been cured.
"This
is one patient. This is early results. We need to see how it works out in other
patients," said her doctor, Haydar Frangoul, at the Sarah Cannon Research
Institute in Nashville.
"But
these results are really exciting."
In Germany,
a 19-year-old woman was treated with a similar method for a different blood
disease, beta thalassemia. She had previously needed 16 blood transfusions per
year.
Nine months
later, she is completely free of that burden.
For
decades, the DNA of living organisms such as corn and salmon has been modified.
But Crispr,
invented in 2012, made gene editing more widely accessible. It is much simpler
than preceding technology, cheaper and easy to use in small labs.
The
technique has given new impetus to the perennial debate over the wisdom of
humanity manipulating life itself.
"It's all developing very quickly," said French geneticist Emmanuelle Charpentier, one of Crispr's inventors and the cofounder of Crispr Therapeutics, the biotech company conducting the clinical trials involving Gray and the German patient.
Crispr made
gene editing more widely accessible - but has given new impetus to the
perennial debate over the wisdom of humanity manipulating life (AFP Photo/ERIC
PIERMONT)
|
"It's all developing very quickly," said French geneticist Emmanuelle Charpentier, one of Crispr's inventors and the cofounder of Crispr Therapeutics, the biotech company conducting the clinical trials involving Gray and the German patient.
Cures
Crispr is
the latest breakthrough in a year of great strides in gene therapy, a medical
adventure started three decades ago, when the first TV telethons were raising
money for children with muscular dystrophy.
Scientists
practising the technique insert a normal gene into cells containing a defective
gene.
It does the
work the original could not -- such as making normal red blood cells, in
Victoria's case, or making tumor-killing super white blood cells for a cancer
patient.
Crispr goes
even further: instead of adding a gene, the tool edits the genome itself.
After
decades of research and clinical trials on a genetic fix to genetic disorders,
2019 saw a historic milestone: approval to bring to market the first gene
therapies for a neuromuscular disease in the US and a blood disease in the
European Union.
They join
several other gene therapies -- bringing the total to eight -- approved in
recent years to treat certain cancers and an inherited blindness.
Serge
Braun, the scientific director of the French Muscular Dystrophy Association,
sees 2019 as a turning point that will lead to a medical revolution.
"Twenty-five,
30 years, that's the time it had to take," he told AFP from Paris.
"It
took a generation for gene therapy to become a reality. Now, it's only going to
go faster."
Just
outside Washington, at the National Institutes of Health (NIH), researchers are
also celebrating a "breakthrough period."
"We
have hit an inflection point," said Carrie Wolinetz, NIH's associate
director for science policy.
These
therapies are exorbitantly expensive, however, costing up to $2 million --
meaning patients face grueling negotiations with their insurance companies.
They also
involve a complex regimen of procedures that are only available in wealthy
countries.
Gray spent
months in hospital getting blood drawn, undergoing chemotherapy, having edited
stem cells reintroduced via transfusion -- and fighting a general infection.
"You
cannot do this in a community hospital close to home," said her doctor.
French
geneticist Emmanuelle Charpentier, one of Crispr's inventors, doesn't believe
in the more dystopian scenarios that have been predicted for gene therapy (AFP
Photo/
ANDER GILLENEA)
|
However,
the number of approved gene therapies will increase to about 40 by 2022,
according to MIT researchers.
They will
mostly target cancers and diseases that affect muscles, the eyes and the
nervous system.
Bioterrorism
Another
problem with Crispr is that its relative simplicity has triggered the
imaginations of rogue practitioners who don't necessarily share the medical
ethics of Western medicine.
Last year
in China, scientist He Jiankui triggered an international scandal -- and his
excommunication from the scientific community -- when he used Crispr to create
what he called the first gene-edited humans.
The
biophysicist said he had altered the DNA of human embryos that became twin
girls Lulu and Nana.
His goal
was to create a mutation that would prevent the girls from contracting HIV,
even though there was no specific reason to put them through the process.
Chinese
scientist He Jiankui, pictured in 2018, used Crispr to create what he called
the first gene-edited humans (AFP Photo/Anthony WALLACE)
|
"That
technology is not safe," said Kiran Musunuru, a genetics professor at the
University of Pennsylvania, explaining that the Crispr "scissors"
often cut next to the targeted gene, causing unexpected mutations.
"It's
very easy to do if you don't care about the consequences," Musunuru added.
Despite the
ethical pitfalls, restraint seems mainly to have prevailed so far.
The
community is keeping a close eye on Russia, where biologist Denis Rebrikov has
said he wants to use Crispr to help deaf parents have children without the
disability.
There is
also the temptation to genetically edit entire animal species --
malaria-causing mosquitoes in Burkina Faso or mice hosting ticks that carry
Lyme disease in the US.
The
researchers in charge of those projects are advancing carefully, however, fully
aware of the unpredictability of chain reactions on the ecosystem.
A picture
taken at the French National Institute of Agricultural Research (INRA) in
Maison-Alfort, on July 20, 2016 shows a tick, whose bite can transmit the Lyme
disease (AFP Photo/BERTRAND GUAY)
|
Charpentier
doesn't believe in the more dystopian scenarios predicted for gene therapy,
including American "biohackers" injecting themselves with Crispr
technology bought online.
"Not everyone
is a biologist or scientist," she said.
And the
possibility of military hijacking to create soldier-killing viruses or bacteria
that would ravage enemies' crops?
Charpentier
thinks that technology generally tends to be used for the better.
"I'm a
bacteriologist -- we've been talking about bioterrorism for years," she
said. "Nothing has ever happened."