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Clinical Trial for Stem Cell Therapy
Reaches Major Milestone
Study demonstrates effects of bone marrow stem cell therapy in a human heart
University of Texas Health Science Center at Houston President James T. Willerson, M.D., and colleagues at the Texas Heart Institute at St. Luke’s Episcopal Hospital announced in July a significant new finding in their clinical trial of adult stem cells to treat patients with severe heart failure.
James T. Willerson, M.D., right, and colleague Emerson Perin, M.D., Ph.D., speak to the news media about results of their clinical trial of adult stem cells to treat patients with severe heart failure. Photo courtesy of Texas Heart Institute
The physicians initiated a study four years ago with colleagues at the Pro-Cardiaco Hospital in Rio de Janeiro, Brazil. The research begun in Brazil has allowed the Texas Heart Institute to have the first FDA-approved clinical trial of adult stem cells – taken from the patient’s own bone marrow – for the treatment of severe heart failure.
“We have demonstrated for the first time in a human heart the effects of bone marrow stem cell therapy,” said Emerson Perin, M.D. Ph.D., director of New Interventional Cardiovascular Technology and medical director of the Stem Cell Center at the Texas Heart Institute. “We analyzed the heart of a patient who underwent stem cell treatment in the study we conducted in Brazil and subsequently died of unrelated causes. We found an increase in the number of blood vessels in the area we injected with stem cells, as well as the presence of substances that indicate cellular regeneration.”
Following the stem cell treatment, the patient had marked improvement in the function of the heart and the blood flow to the heart as evidenced by imaging procedures physicians conducted in follow-up examinations.
“We believe this will be the first time in the world that we’ve had the opportunity to examine a human heart following treatment for severe heart failure in which stem cells taken from a patient’s own bone marrow are injected directly into injured but still viable portions of the heart muscle. We believe this is an unequivocal demonstration of marked improvement in blood flow,” said Willerson, who is president- elect and medical director of the Texas Heart Institute.
The physicians say that in animal models, the stem cells they use differentiate into new blood vessel cells and they acknowledge that it’s also possible that the stem cells stimulate local factors in the heart – cytokines and angiokines – which recruit additional stem cells to the heart to promote new blood vessel development to improve blood flow.
“In any event, we believe this is the first time we have achieved clear documentation in a human heart that there is formation of new blood vessels at the site of stem cell injections and we’re very excited about that,” Willerson said.
The Texas Heart Institute at St. Luke’s initiated the FDA-approved blinded, randomized clinical study in April 2004. Researchers continue to enroll patients in the Phase I trial, which focuses on the safety and efficacy of the treatment. In all, 20 patients will be randomized to receive the treatment and 10 will serve as controls. Those patients who do not receive the treatment will have the option to do so after six months of evaluation.
The treatment involves using a special catheter threaded through the groin. The doctors use an innovative mapping technology to identify areas in the heart that have sustained mechanical and electrical damage. Using that same catheter, doctors can inject millions of stem cells directly in the left ventricle along the periphery of the damaged area.
The study was at one time limited to patients in the greater Houston area but is now open to all interested patients with severe heart failure. To be considered for the study, patients can call (832) 355-6555 or e-mail their contact information to stemcell@heart.thi.tmc.edu.
A paper on this latest development of the research is now available at the subscription-based Web site of Circulation, the American Heart Association’s premier journal, at http://circ.ahajournals.org, and in the July 26 paper edition of Circulation.