WSJ BLOG/Health: Some Promising Findings on Embryonic Stem Cells
Last Update: 1/23/2012 5:02:33 PM
(This story has been posted on The Wall Street Journal Online's Health Blog at
blogs.wsj.com
By Katherine Hobson
Very early results fromresearch into embryonic stem cell treatments suggest that
the therapy was safe in use against macular degeneration, a major cause of
blindness. The findings, though preliminary, are the first published results
involving embryonic stem cells in human patients.
In the report, which covered two patients followed over four months, the patients
reported some visual improvement that may -- or may not -- spring from the
treatment. But much more research needs to be done before the therapy can be
deemed a success.
Writing in the Lancet, researchers from biotech firm Advanced Cell Technology and
the University of California, Los Angeles reported turning human embryonic stem
cells into the key cells lost in macular degeneration, known as retinal pigment
epithelial cells. Two legally blind patients then had these cells surgically
implanted into one eye.
The patients -- one with dry age-related macular degeneration and one with a
related condition called Stargardt's macular dystrophy -- showed no signs of the
safety problems that have been a worry with embryonic-stem-cell-derived therapy.
"There were no tumors, and there was no immune rejection" after patients were
tapered off of immunosuppressive drugs, said Steven Schwartz, an author of the
study and chief of the retina division at UCLA's Jules Stein Eye Institute.
The patients also reported visual changes that "could be a sign of improvement,"
said Dr. Schwartz. For instance, the Stargardt's patient, in her 50s, went from
discerning only hand motions to being able to count fingers. She also reported
improved color vision.
But Dr. Schwartz cautioned that the improved vision reported by the patients
might be chalked up to the placebo effect, the surgery, the immunosuppressive
drugs or "all of the above," he said. "Objectively, there is no consensus in how
to measure vision in low-vision patients," he said.
The clinical trials studying the drugs in the two different forms of macular
degeneration will eventually include 24 patients at different centers, followed
intensively for a year and then tracked for years afterwards, said Robert Lanza,
an author of the study and chief scientific officer at Advanced Cell Technology,
which is developing the therapy and funded the research. He said if studies in
these patients with advanced disease pan out, eventually the aim is to target
patients at much earlier stages of macular degeneration.
Dr. Lanza said even limited data from two patients is "of great value to the
scientific community" because of the safety concerns that have surrounded
embryonic stem cell research.
The research has also been controversial for ethical reasons, given that the
extraction of stem cells from a human embryo results in the destruction of the
embryo, which some critics say amounts to taking human life. Stem cells can
develop into any kind of tissue.
The research is difficult and resource-heavy. Another company, Geron Corp. said
in November it would exit the entire field of embryonic stem cell research,
citing financial constraints. As part of that move, it halted a small trial of
embryonic stem cells in people with spinal-cord injuries. That study had been the
first trial of the technology to be approved in humans.
Dr. Lanza said this work also "paves the way" for working with so-called induced
pluripotent stem cells, adults cells taken from the patient and reprogrammed back
to an earlier state. Those have the benefit of avoiding the ethical issues
surrounding embryonic cells as well as the prospect of rejection by the body.
Image of embryonic stem cells via NIH Image Bank
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