Embryonic Stem Cells Restore Vision In Preliminary Human Test
October 14, 2014
http://www.npr.org/blogs/health/2014/10/14/346174070/embryonic-stem-cells-restore-vision-in-preliminary-human-test
Isabella Beukes, of Santa Rosa, Calif., has been legally
blind for more than 40 years. An experimental treatment derived from
embryonic stem cells seems to have enabled her now to see not just color
but also some shapes.
Scientists are reporting the first strong evidence that human embryonic stem cells may be helping patients.
The
cells appear to have improved the vision in more than half of the 18
patients who had become legally blind because of two progressive,
currently incurable eye diseases.
The researchers stress that
the findings must be considered preliminary because the number of
patients treated was relatively small and they have only been followed
for an average of less than two years.
But the findings are
quite promising. The patients had lost so much vision that there was no
expectation that they could benefit, the researchers say.
"I'm astonished that this is working in the way that it is — or seems to be working," says Steven Schwartz, a UCLA eye specialist who led the study, which was published Tuesday in the British medical journal The Lancet. "I'm very excited about it."
Other researchers agreed the work is preliminary, but also highly promising.
"It really does show for the very first time that patients can, in fact, benefit from the therapy," says Dr. Anthony Atala, a surgeon and director of the Wake Forest Institute for Regenerative Medicine at Wake Forest University.
"That allows you to say, 'OK, now that these cells have been used
for patients who have blindness, maybe we can also use these cells for
many other conditions as well, including heart disease, lung disease and
other medical conditions,' " Atala says.
Human embryonic stem
cells have the ability to become any kind of cell in the body. So
scientists have been hoping the cells could be used to treat many
diseases, including Alzheimer's, diabetes and paralysis. But the study
is the first human embryonic stem cell trial approved by the Food and
Drug Administration that has produced any results.
"It is really a very important paper," Atala says.
The study involved patients suffering from age-related macular degeneration and Stargardt's macular dystrophy,
the two leading causes of adult and juvenile blindness in the developed
world, Schwartz says. The diseases destroy a person's central vision.
"Whatever
you're looking at is gone — whether it's faces, or reading or food on a
plate, or whether something is a step or stripe," Schwartz says. "It's
very, very difficult to perform activities of daily life that we, you
know, don't even think about."
Working with Advanced Cell Technology Inc.
of Marlborough, Mass., Schwartz and his colleagues took human embryonic
stem cells and turned them into the kind of cells that are killed by
these diseases — retinal pigment epithelial cells. Then, they infused
between 50,000 and 150,000 cells into the retinas of the patients.
"What
we did is put them into patients who have a disease where those
particular cells are dying; and we replaced those dying tissues with new
tissue that's derived from these stem cells," Schwartz said. "In a way
it's a retinal transplant."
No one expected the cells to help any of these patients see
better, because the study was designed mostly just to see if doing this
was safe. Researchers were concerned the cells could destroy whatever
vision was left or lead to tumors in the volunteers' eyes. So Schwartz
picked patients whose eyes were so far gone that they weren't risking
losing any vision. That also meant that there was little hope the cells
could help either.
"We did not expect to help these patients, and they did not expect to be helped," Schwartz says.
Some
patients experienced side effects from the procedure itself and from
the drugs they had to take to suppress the immune system, but none of
the side effects were considered serious. The cells themselves have
produced no safety problems so far, the researchers reported.
And,
surprisingly, many of the patients did start to see better, according
to the report. Ten of the 18 patients can see significantly better. One
got worse, but the other seven either got better or didn't lose any more
vision.
"These are patients that didn't see better for 30
years and all of a sudden they're seeing better," Schwartz says. "It's
amazing."
The patients include a graphic artist who could
suddenly make out the woodwork carved on a piece of furniture in her
bedroom, an international consultant who regained the ability to walk
through busy airports without help, and an elderly rancher who's riding
his horse again, Schwartz says.
"He couldn't see things like a
barbed-wire fence or whether in the distance a stray cow was under a
tree," Schwartz says. "And six months after the transplant he's back to
running his cattle again. And he can, in fact, see a snake on the ground
or sort of tell whether a distant shadow is a cow or something else. So
it's made a big difference for him in his life."
Isabella
Beukes of Santa Rosa, Calif., has been legally blind for more than 40
years. But within weeks of getting the cells, she started to see better.
She could make out the cursor on her computer screen and the color of
her clothes. Today, she can hike the hills near her house all by
herself.
"The improvement, I mean, from where I was coming is
just, it's very, very significant for me. I think it's fantastic,"
Beukes says. "I just think to be part of groundbreaking research work is
amazing."
Just being able to see well enough to to hike the hills
around her Santa Rosa home by herself is a huge improvement, Beukes
says.
Tim Hussin for NPR
The research is controversial, however. Embryos are destroyed to get the cells, and some people think that's immoral.
"The
problem we have with embryonic stem cells is simply the fact that you
have to destroy a young human being to get embryonic stem cells," says David Prentice,
senior fellow for life science at the Family Research Council, an
advocacy group. "We would reject the idea that any human being be
destroyed for experimental purposes."
For his part, Schwartz
says he's just trying to help blind people see better. But he cautions
that this work is still at a very early stage.
"I don't want
patients to come in to their doctor saying, 'Hey, I heard about the stem
cells on the radio and I'd really like to get that treatment done, and
what do you think?' " he says. "It's not ready. Maybe in a few years.
Maybe not. We have to wait and see. The jury is way out still."
Schwartz
has continued treating more patients using larger doses of cells and
trying it on patients who haven't lost as much vision to see if that
works even better. He has also expanded his study to Boston, Miami,
Philadelphia and London.
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