Coronary Artery 311.
(photo credit: Creative Commons)
ORLANDO, Fla - A stem cell therapy for treating patients experiencing moderate to severe heart failure showed real promise in preventing serious consequences or death, according to data from a small mid-stage clinical trial.
The treatment from Australia's Mesoblast Ltd, known as revascor, appeared to be safe and reduced by 78 percent the rate of major adverse events -- heart attacks, cardiac death and need for artery clearing procedures -- after one year compared with patients who received the standard of care.
The findings from the 60-patient trial were presented on Monday at the American Heart Association scientific meeting in Orlando and were deemed to be statistically significant, despite the small size of the study.
"It is extremely surprising and really incredible to see that there are
less cardiac deaths and less MACE (major adverse cardiac events) events
in the treated population and that is over a long period of follow-up,
in some patients close to three years, so that's very impressive," said
Dr Emerson Perin, the study's lead investigator.
"If we have the
same findings in a larger study, we think we've got something that will
be an approvable therapy," Perin, from the Texas Heart Institute in
Houston, said in an interview.
Mesoblast and its partner Teva
Pharmaceutical Industries, which recently acquired original partner
Cephalon, said they plan to start enrolling patients in a much larger
Phase III trial in the first half of next year.
Safety was the
primary goal of the Mesoblast study and there were no cases of adverse
events attributed to the Mesoblast stem cells, researchers said.
Closer to treatment?
have been studying stem cells from numerous sources for more than a
decade with the hope that their ability to transform into a wide variety
of other types of cells would help treat many types of illness and
injuries, from spinal injuries to heart disease. Several companies
appear to be closing in on turning therapeutic promise into viable
The Mesoblast therapy uses adult stem cells derived
from bone marrow known as mesenchymal precursor cells. The cells are
delivered by catheter directly to the heart on the theory that they will
help stimulate growth of blood vessels.
The cells are provided by a healthy, unrelated donor. As a result, the
first hurdle is to make sure patients do not develop significant
antibodies to the cells.
None of the heart failure patients who received the cells became overly
sensitized or made significant antibodies to the cells, so no
significant immune response was seen, researchers said.
Patients in the study had moderate to severe heart failure, a condition
in which the heart muscle shows diminished capacity to pump blood. The
study subjects had an ejection fraction, or fraction of blood pumped out
of the left and right ventricles, of less that 40 percent. For a
healthy person it should be greater than 55 percent.
There was no significant improvement in ejection fraction seen in
patients who received the stem cell therapy, but there was a trend
toward improvement in a six-minute walking test, which can be an
indication that patients are feeling better.
The study tested three doses, or concentrations, of cells -- 25 million
cells, 75 million cells and 150 million cells -- with 15 patients in
each group and 15 additional patients receiving optimal standard of
care. Based on findings from this Phase II study, the companies said
they expect to move into the pivotal human trials with the 150 million
"The high dose had no heart failure hospitalization and no cardiac deaths," Perin said.