* Mesoblast's revascor seen safe in Phase II study
* Cut major adverse heart events by 78 pct
* Phase III trial expected to start in 2012
By Bill Berkrot and Lewis Krauskopf
ORLANDO, Fla, Nov 14 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
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
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 A TREATMENT?
Researchers 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
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 cell dose.
"The high dose had no heart failure hospitalization and no
cardiac deaths," Perin said.