Testing Adult Stem Cells and Potential Hope for Heart Disease Victims
4 Apr, 2007 02:28 pm
Dr. Amish Raval and his team at the University of Wisconsin Hospital and Clinics in Madison, Wisconsin recently announced that it is one of the first medical centers in the United States participating in an important study investigating adult stem cells to treat patients with chronic myocardial ischemia. The ?Autologous Cellular Therapy CD34+ Chronic Myocardial Ischemia (ACT34-CMI) Trial? is currently the largest cell therapy study in the U.S. and is designed to study if blood-derived stem cells can improve improve symptoms and clinical outcomes in patients with refractory angina.
ACT34-CMI is a prospective, randomized, double-blind, placebo-controlled study that is set to enroll 150 patients in the U.S. The University of Wisconsin is one of approximately 20 research sites nationwide participating in the study, which is sponsored by Baxter Cellular Therapies, a division of Baxter Healthcare Corporation. Baxter technology is used to select the subject’s own CD34+ stem cells that are under investigation in this trial.
At baseline, subjects report chest pain frequency and undergo several imaging tests. Next, subjects receive a series of subcutaneous injections a protein to release the cells from the bone marrow into the blood circulation, a process called "mobilization". Thereafter, the cells are collected by using a process called "apheresis" and finally, the adult stem cells are enriched and concentrated. Cardiologists then map the heart with a catheter system to identify parts of the heart with limited blood supply as targets for cell delivery. Subjects are randomly assigned one of two dosing levels of stem cells or placebo. Neither the investigators nor the patients know which treatment is being delivered. An investigational catheter injection system is delivers the stem cells or placebo directly into the heart. Follow-up examinations, including subjective improvement in chest pain frequency and objective imaging tests such as MRI are performed for 12 months.
The first patient enrolled at the University of Wisconsin had failed bypass surgery, failed balloon angioplasties attempts, and was still having exertional chest pain despite maximal medication therapy. The screening, stem cell mobilization phase, stem cell collection procedure and the heart injection procedure went uneventfully, and he recovered well. What is particularly remarkable about trials of this nature is the multi-disciplinary team approach required. Interventional cardiologists, hematologists, stem cell processing technicians, apheresis nurses, study nurses, cardiac catheterization laboratory personnel and medical house-staff are among the many skilled professionals necessary to properly execute these trials.
The University of Wisconsin School of Medicine and Public Health is a clear leader in the field of regenerative medicine. The pioneering work of Dr. Jamie Thompson who was first in the world to isolate human embryonic stem cells, and subsequent work by internationally acclaimed scientists have helped pave the way for multiple initiatives at UW, including this clinical trial to explore the treatment potential of adult stem cells.
CD34+ bone marrow-derived cells have the potential for a contribution to new blood vessel formation as well as for a stimulation of cardiomyocytes through secreted factors after injection into heart wall. Therefore, current experimental and clinical trial data indicate that there may be a great benefit to use of CD34+ cells for heart failure patients to improve their heart function.