Stem Cell Drug Fails in Testing
The drug, developed by Osiris, was the closest to market.
A drug
derived from bone marrow cells has failed two late stage clinical trials,
representing a major setback for stem cell medicine. The drug, developed by Osiris, a stem cell company based in
Maryland, is considered the closest to market of all the stem cell-based products in
human testing.
The
announcement follows another significant setback for the field. Last month,
Geron, an embryonic stem cell company based in California, announced that its
clinical trial for spinal cord injury–set to become the first human
trial of human embryonic stem cells–was put on hold by the Food and Drug
Administration after animal studies showed that the treatment was linked to
increased development of small cysts at the injury site.
Osiris’s drug, called prochymal, is
a preparation of mesenchymal stem cells (MSCs) isolated from the bone marrow of
healthy young adult donors. Research in animals suggests that these cells can
reduce inflammation and spur tissue healing by stimulating the release of
molecular growth factors.
This story is only available to subscribers.
Don’t settle for half the story.
Get paywall-free access to technology news for the here and now.
Subscribe now
Already a subscriber?
Sign in
The drug is
also being tested in clinical trials for myocardial infarction, chronic
obstructive pulmonary disease (COPD) and type 1 diabetes. Osiris halted a
late-stage clinical trial of prochymal for Crohn’s disease, a form of
inflammatory bowel disease,
earlier this year because of the high placebo response rate.
According to an article in The
New York Times:
Stem cells, particularly in the form of bone marrow transplants, are already
used in medicine. Osiris is hoping that Prochymal will become the first stem
cell product approved by the Food and
Drug Administration and sold as a mass-produced pharmaceutical product.
But the failure in the two trials could make it hard to reach that goal.
Both trials tested Prochymal as a treatment for graft-versus-host
disease, which occurs when immune cells in donated marrow attack the
recipient’s organs as foreign tissue.
In one trial, in which Prochymal was used
along with steroids, 45
percent of patients responded to Prochymal and steroids compared with 46
percent who had a response to steroid and a placebo.
In a second trial, in which Prochymal was
tested in patients who were not benefiting from steroids, 35 percent of those
getting the drug had a resolution of graft-versus-host disease for at least 28
days, compared with 30 percent getting the placebo. The difference was not
statistically significant.
Osiris said, however, that in the second
trial, the drug did provide a statistically meaningful benefit in patients
having graft-versus-host disease that specifically affected their livers or
their gastrointestinal tracts.