New stem cell therapy used against a range of illnesses
New stem cell therapy in use against a range of illnesses
By DORSEY GRIFFITH
McClatchy Newspapers
Article Last Updated: 12/19/2007 08:57:10 AM PST
SACRAMENTO — They are not from human embryos, but the stem cells
being packed into the spine of Perry Anderson may help him heal from
a surgery that failed to heal the first time, leaving him hobbled and
unable to work for nearly three years.
The same cells, derived from bone marrow, may also one day help heart
attack patients recover, ease the misery of inflammatory bowel
disease, and allow diabetics to continue producing insulin.
While the ethical debate rages over the use of stem cells taken from
discarded human embryos, bone marrow stem cells, harvested both from
cadavers and from live donors, are being developed for use against a
range of illnesses.
These cells have shown a remarkable ability to form bone, cartilage,
tendons, ligaments and fat, and are proving useful in experimental
drug therapies to control diseases caused by the sometimes harmful
effects of the body's own immune system.
In Sacramento, Dr. Pasquale Montesano is using them in spine surgery.
At the University of California-Davis, stem cell scientist Jan Nolta
will try an adult stem cell-based drug in patients with Crohn's, a
chronic and painful bowel disease.
More formally called mesenchymal stem cells, or MSCs, they come from
the tissue tucked inside the bone cavity.
The U.S. Food and Drug Administration has approved only one MSC-
derived product. Trinity, by Maryland-based Osiris Therapeutics Inc.,
was approved in 2005 for use in bone repair surgeries. It is marketed
as an alternative to allograft, a separate surgical procedure in
which the patient's own bone is taken from the hip and implanted
elsewhere in the body.
Trinity (also sold under the name Osteocel) costs about $450 per
milliliter, an amount equivalent to a quarter teaspoon. A typical
spinal surgery would require two to four milliliters of the product.
Unlike a drug, Trinity is regulated as a human cell and tissue-based
product. As such, its manufacturer cannot manipulate the cells by
expanding them or adding drugs to them.
The MSCs used to make Trinity are taken from human cadavers the same
way hearts, kidneys, livers and corneas are harvested after death and
donated for transplantation.
Earlier this month, they arrived in the operating room at Sutter
Memorial Hospital in Sacramento in a tiny jar carefully packed in dry
ice and stored in a foam cooler. Kept frozen, they can last up to
five years. Once removed, they must be used within 48 hours to be
viable.
Montesano, the spine surgeon, says it's worth the trouble. He says
Trinity works as well as other, costlier options, and is especially
useful in patients like Anderson, whose prior spine fusion surgery
failed.
Anderson was a painter when he fell from a 6-foot ladder and injured
his back in 2004. A bad disc pinching a nerve in his neck caused him
pain and searing headaches. Surgery to remove the disc and fuse the
vertebra in August 2006 never completely healed.
"The headaches aren't as bad, but my hands get numb, my arms are
aching, I have lower back pain, anxiety attacks and depression,"
Anderson, 42, said before his second surgery. "I have worked since I
was 17. Now I can't do anything. I can't mow the yard, I can't go
grocery shopping. It's ridiculous."
Montesano first removed the scar tissue and bony fragments from
between the damaged vertebra, careful to avoid his carotid artery and
spinal cord.
Then, he took a graft made from cadaver bone and shaped like a square
nut from a hardware store, widened the hole through the middle of it
and packed it, like a sushi roll, with the crystal-like stem cells.
After gently placing the graft into Anderson's spine, he tucked more
cells around it.
When implanted in an area where new bone is needed to repair damage,
Trinity preferentially forms new bone, said Bob Zambon, an Osiris
scientist.
Montesano completed Anderson's operation by screwing into his spine a
small metal plate to anchor the bone in place while it heals.
"Now we have to let Mother Nature take its course," he said.
Although an estimated 5,000 spine procedures with Trinity have been
done so far in the United States, the data on how well it works in
humans are not complete, and researchers still don't know whether
it's superior to other technologies used to promote bone formation.
Nevertheless, the product already has generated $22 million in sales,
and surgeons like Montesano say the high demand for it limits their
ability to use it.
Dr. Kee Kim, a neurosurgeon at the University of California-Davis,
said even without the final human data, the university is evaluating
Trinity and expects he will be using it within months.
Mesenchymal stem cells taken from live donors also are being obtained
by a handful of companies worldwide to develop drugs. Clinical trials
using MSCs are under way in Iran for use against cirrhosis, in
England against multiple sclerosis, and in Japan for severe gum
disease.
The beauty of MSCs, said Zambon, is that once harvested they can be
expanded in culture and used in patients in the quantities their
bodies need but can't naturally produce. In addition, patients in
clinical trials treated with MSC-based drugs do not require other
medication to prevent rejection.
One experimental MSC-based drug, by Osiris, is being fast-tracked
through the FDA because of its promise against a deadly complication
of bone marrow transplantation called graft vs. host disease.
In these cases, typically seen in childhood cancers, bone marrow
transplanted to save a life actually rejects the patient's body often
attacking the child's skin, eyes, stomach and intestines.
The Osiris drug, called Prochymal, works to suppress the patient's
immune system and arrest the damage. The drug also is being used in
trials to address type I diabetes, a disease in which the body's beta
cells are destroyed by the immune system.
At the University of California-Davis, researchers in 2008 will begin
recruiting patients with Crohn's disease, an inflammatory bowel
disorder. Participants, who have failed other treatments, will be
given Prochymal.
"These cells are incredibly special because they temporarily stop the
immune reaction against the bowel at the local level," said stem cell
researcher Nolta. "And that allows them to heal."
http://www.monterey
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StemCells subscribers may also be interested in these sites:
Children's Neurobiological Solutions
http://www.CNSfoundation.org/
Cord Blood Registry
http://www.CordBlood.com/at.cgi?a=150123
The CNS Healing Group
http://groups.yahoo.com/group/CNS_Healing
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