Stem cell research got its latest boost. For the first time, stem cells were injected into the hearts of humans who had suffered serious heart damage, and patients improved dramatically. The scientists found that the stem cells grew into new heart cells to replace the damaged tissue.
In the new study, just published in The Lancet, a group of researchers led by Robert Bolli grew stem cells from patients’ own hearts, after the patients had suffered serious heart attacks, leaving their hearts permanently damaged. Bolli and colleagues collected a small amount of tissue from each patient’s own heart, and purified stem cells from that tissue. By using the patient’s own cells, there is no danger of rejection as there would be with cells from an unrelated donor.
They measured the patients’ heart function by how much blood was being pumped through the left ventricle. The patients had an average Left Ventricular Ejection Fraction (LVEF) of 30.3% at the beginning of the study, an indication of very severe heart disease.
Four months later, the 16 patients who received the stem cells had an average LVEF of 38.5%, while patients in the control group (who didn’t get the stem cells) showed no change. Even more dramatically, after one year the patients LVEF had improved further, to 42.5%. The researchers used MRI to measure the damaged heart tissue in 7 of their patients, and found that it had actually decreased by 30% after one year.
In a companion trial at Cedars-Sinai Heart Institute in Los Angeles, Dr. Eduardo Marbán reported similarly positive results. Marbán said that the patients grew approximately 600 million new heart cells after the procedure, comparable to the number of cells that die in a serious heart attack.
The results are very preliminary, and only a few patients have been treated so far, but this is a major triumph for stem cell research. The research in question used adult stem cells, but embryonic stem cells may prove even more effective, and may be easier to obtain because they don’t have to come directly from someone’s heart.
Now dozens of adult stem cell treatments are moving through clinical trials and showing early success, raising hopes that some could reach the market within five years.
“It will only take a few successes to really change the field,” said Gil Van Bokkelen, chief executive of Athersys Inc and chairman of the Alliance for Regenerative Medicine. “As you see things getting closer and closer to that tipping point, you're going to see a frenzy of activity take place.”
Many of the trials focus on heart disease and inflammatory conditions, some of the biggest markets in medicine. The cells used are derived from adult tissue such as fat, or bone marrow, thereby circumventing the ethical concerns raised by the use of cells derived from embryos.
“A lot of big companies are looking to place bets on some Phase II products once that data has been confirmed,” said Paul Schmitt, managing partner at venture capital firm Novitas Capital. “Even now they're attending all the medical meetings and talking to all the stem cell companies.”
“My philosophy in the stem cell space is that it's very difficult at this point to pick the winners and losers,” said Steven Martin, managing member at Aspire Capital Partners LLC. “We believe that over time there will be some very significant clinical progress, and valuations will improve, but we're still a long way from an approved therapy.” In the meantime, he said, “we are willing to be patient because we think the upside is tremendous.”
Pfizer Inc, Johnson & Johnson and Roche Holding AG are members of the Alliance for Regenerative Medicine, a nonprofit group that promotes awareness of the field. Pfizer has a regenerative medicine unit and a partnership with Athersys. But their projects are small.
Different types of stem cell are being used for different diseases. Cytori is developing a heart disease product derived from fat cells, for example, while Celgene is using placental cells for Crohn's disease and rheumatoid arthritis therapies. Fetal cells are also being explored. Neuralstem Inc, for example, is developing treatments for neurological disorders from an aborted fetus and is in the early stages of testing a treatment for amyotrophic lateral sclerosis, known also as Lou Gehrig's disease.
Recently, Geron Corp, the world's leading embryonic stem cell company, said it could no longer fund its stem cell work and would focus on developing cancer drugs. It closed its trial for spinal cord injury.
Some believe the regulatory hurdles for treatments derived from a patient's own cells will be lower than those where the cells come from donors, since there is less risk of cell rejection. However, no clear pathway has yet been established. “We need a clear, consistent and rigorous regulatory framework,” said Athersys's Van Bokkelen “The FDA is actually willing to provide lots of guidance and assistance to sponsors, if you just ask them.”
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