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Senior Citizen Health & Medicine
Study Investigates Use of Stem Cells to Treat Severe
Coronary Artery Blockage
First human Phase II adult stem cell therapy study in
the U.S.
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 Steve Myrah has traveled
to Costa Rica and Belize to admire exotic birds. He's journeyed
to South Africa on an animal-watching excursion. And this
summer, the 68-year-old retired university administrator and his
wife are planning to sail the Aegean Sea.
He's traveled the world,
but Steve Myrah can't walk a block down his own street without
having chest pains.
Having suffered from
severe coronary artery disease since his mid-40s, Myrah is
participating in a trailblazing clinical trial investigating
whether a person's own stem cells can stimulate the growth of
new blood vessels in the heart.
"I used to walk home
four miles from work. I mean, I used to cross-country ski and go
hiking, and now I can't do any of that without getting angina,"
says Myrah, a Middleton man who is the first patient to be
enrolled in the University of Wisconsin School of Medicine and
Public Health portion of the national study, sponsored by the
Cellular Therapies business unit of Baxter Healthcare
Corporation.
Read the story at
UW Health,
click here. |
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March 13, 2007 - The University of Wisconsin School
of Medicine and Public Health is among the first medical centers in the
country taking part in a novel clinical trial investigating if a
subject's own stem cells can treat a form of severe coronary artery
disease.
The trial, just underway at UW Hospital and
Clinics, is enrolling subjects in the Autologous Cellular Therapy
CD34-Chronic Myocardial Ischemia (ACT34-CMI) Trial. The first patient
underwent the procedure March 7. Because the study is randomized and
"double-blinded," however, neither the patient nor the research
physician knows if he received his own stem cells or a placebo
substance.
This trial is the first human Phase II adult stem
cell therapy study in the U.S. Its goal is to investigate the efficacy,
tolerability, and safety of blood-derived selected stem cells to improve
symptoms and clinical outcomes in patients with chronic myocardial
ischemia (CMI), a severe form of coronary artery disease.
Myocardial ischemia, which affects hundreds of
thousands of people, is a serious heart condition that involves
narrowing of coronary arteries and results in limited blood flow to the
heart. A person who suffers from chronic myocardial ischemia continues
to experience insufficient flow of oxygen-rich blood to the heart
despite optimum medical intervention.
"This type of therapy - regenerative medicine -
treats diseases by using growth factors, genes or stem cells to promote
blood vessel or tissue growth," explains Amish Raval, head of
cardiovascular regenerative medicine at UW Health. The goal with this
approach, he says, is to promote either angiogenesis, which is the
growth of new capillaries; arteriogenesis, or the maturation and
enlargement of existing arteries and arterioles; or vasculogenesis, the
sprouting of new arteries and arterioles.
The stem-cell study is considered the "gold
standard" of research design: a prospective, randomized, double-blind,
placebo-controlled study that involves adult subjects who have severe
coronary artery disease, are currently on maximal medical therapy and
are not suitable candidates for conventional procedures (such as
angioplasty, stents, or coronary artery bypass surgery) to improve blood
flow to the heart.
UW Hospital and Clinics is one of 15-20 research
sites nationwide participating in the study, which is sponsored by the
Cellular Therapies business unit of Baxter Healthcare Corporation.
Baxter technology is used to select the subject's own CD34+ stem cells
that are under investigation in this trial.
The first step in the ACT34-CMI trial is to
establish the baseline of how often the study subjects have chest pain
related to their heart disease and the severity of the pain. Next, all
subjects receive a series of needle shots, typically delivered under the
skin in the arm, thigh or abdomen of a commercially produced protein
(granulocyte colony stimulating factor). The protein helps to release
blood-forming CD34+ cells from a subject's bone marrow into the
bloodstream.
Then, investigators use a cell separation system to
remove from the subject's bloodstream a mix of cells containing the stem
cells. When this process, known as apheresis, is complete, technologists
further process the collected stem cells to select the CD34+ stem cells
for use in this investigational therapy.
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Amish Raval, MD
(pictured) is UW's principal investigator in a trailblazing
clinical trial. |
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UW Health interventional cardiologists then "map"
the heart with a catheter-based, non-surgical system to identify regions
of the heart as targets for cell delivery. The researchers then use a
special investigational catheter system to deliver either CD34+ cells or
placebo into areas of the heart that have poor blood flow. Subjects are
randomly selected to receive either one of two dosing levels of CD34+
stem cells, or placebo. Subjects will receive follow-up examinations for
12 months following the investigative procedure.
"The initial results from Phase I of the trial were
encouraging," Raval says. "Subjects reported feeling better with
reductions in chest pain and improved exercise capacity during the early
stage of the trial. That's encouraging to us."
Coronary artery disease is the most common form of
heart disease and is the leading cause of death in the United States.
This condition occurs when the coronary arteries and the smaller vessels
that supply oxygen-rich blood to the heart muscle become narrowed or
blocked by plaque deposits and blood clots. Poor blood flow and blood
clots "starve" and injure the heart muscle.
The American Heart Association estimates that every
year, between 125,000 and 250,000 individuals with coronary artery
disease develop chronic myocardial ischemia (CMI), one of the most
severe forms of coronary artery disease, which can cause unstable
angina, heart attacks and progressive heart failure when adequate blood
flow is not restored. CMI develops when the coronary arteries become so
diseased that they limit the flow of blood to the heart and send small
blood clots downstream, blocking the small blood vessels in the heart.
These blockages can result in a series of
mini-heart attacks that, while they may be too small to notice at the
time, in aggregate cause significant long-term damage to the heart
muscle and disability to the patient. While cardiologists can restore
blood flow in some cases, the heart muscle can be irreversibly damaged,
leading to significant disability, progressive heart failure and often
death.
Study enrollment details
Subjects in the current phase II study are randomly
selected to receive either one of two dosing levels of CD34+ stem cells,
or placebo. Researchers will conduct follow-up examinations for 12
months following the investigative procedure.
To be included in the study, patients must:
● Be at least 21 years
old
● Experience chronic
chest discomfort at rest and with minimal exertion
● Have found
inadequate relief from medications
● And be unsuitable candidates for conventional
revascularization techniques, such as surgical bypass, angioplasty or
stents
For more information, contact study coordinator
Soni Vander Ark, RN, at (608) 265-0612.
Learn more about UW Health services
>>
Wisconsin School of Medicine and
Public Health
>>
UW Hospital and Clinics
>>
Heart & Vascular Care »
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