Docs fix hearts with stem cell injections
Doctors have rejuvenated post-heart attack patients by injecting them with stem cells, said two studies released Sunday.
The clinical trials delivered stem cells to hearts whose stiff, post-attack scar tissue kept them from pumping blood as they should, according to the studies presented at the American College of Cardiology meeting of 30,000 specialists in New Orleans, Louisiana until March 27.
One of the trials used stem cells from bone marrow, a first for cardiology, according to the study's lead author, Joshua Hare of the University of Miami medical school in Florida.
Among stem cells's many advantages is that they can be harvested from donors genetically dissimilar to the recipient, and they attach themselves at the point of an injury, Hare told reporters.
Hare and his team injected intravenously 53 patients within 10 days of a heart attack. They randomly assigned patients different doses (0.5 million 1.6 million or 5.0 million cells per kilogram) and compared the dosages with a placebo.
Over six months, the patients receiving the stem-cell treatment had better heart and lung function with fewer arrhythmias.
Echocardiography also showed better heart function, especially in patients with greater heart damage.
"This trial makes an important contribution in the field of stem cell-based treatments for heart disease by providing safety and efficacy data for a unique and promising type of stem cell to treat cardiac damage," Hare said.
"This study represents a first step," Hare said. "We must perform additional and larger trials to determine the real-world application of (marrow stem cells) to fight heart disease."
The second study tested stem cells taken from the patients' own muscle tissue.
Nabil Dib of the University of California led the team testing 23 patients with progressive, congestive heart failure.
Researchers gave the control group of 11 patients standard drug treatments, while those in the treatment group received doses of 30 million, 100 million, 300 million or 600 million muscular stem cells injected into their hearts.
After six months the stem-cell recipients had markedly improved quality of life, while the control group worsened.
"Transplantation using a minimally invasive catheter is safe, showed improvement in quality of life and may have the potential to improve cardiac function," Dib said.
The US Food and Drug Administration, which vets trials, will allow a phase II randomized, double-blind, placebo-controlled clinical trial for up to 160 patients, he said. https://www.physorg.com/news94104798.html
Long Road Ahead For Heart Stem Cells
Robert Langreth 03.27.07, 6:00 AM ET
New Orleans -
Shares of biotech firm Osiris Therapeutics surged 15% to $20.50 in Monday trading after intriguing trial results showed that the company's new stem cell therapy for the heart was safe. But doctors at a major cardiology meeting where the research was presented said years more study will be needed before this or other stem cell treatments for the heart might be ready for routine use.
Data from trials of two different types of stem cells to help sick heart patients were presented at the American College of Cardiology confab yesterday, both involving adult stem cells. The Osiris (nasdaq: OSIR - news - people ) approach involves infusing cells derived from the bone marrow called mesenchymal stem cells into patients blood after a heart attack. The cells do not regenerate new heart muscle directly, but some migrate to the heart and may stimulate healing processes.
Cardiologist Joshua Hare of the University of Miami presented results of a 53-patient trial in which the Osiris therapy was compared to placebo in heart attack patients. The study found no serious side effects, and it also found hints of a benefit. In particular there was an unexpected reduction of heart arrhythmias in patients who got the stem cells, and there was an improvement in lung function in stem cell patients.
"This is the first in a series of attempts to heal heart patients after a heart attack," said Hare, who led the study. "We think the stem cells stimulate the healing properties of the heart."
The second study involved 23 chronic heart failure patients and took a total different approach. Researchers at UCSD removed thigh cells from each patient and then sent it to a small company, Mytogen, which isolated muscle-forming cells called myoblasts from the muscle and divided them in the lab over several weeks until there were hundreds of millions of them. The UCSD researchers then inserted a special catheter into the hearts of the patients and injected millions of the myoblast cells into the areas where they found damage. The hope was that these cells would form new heart tissue in damaged areas.
The cells were safe, and there were signs of effectiveness, said UCSD's Nabil Dib, who led the trial. In particular, echocardiogram assessments revealed that bloated hearts of the sick patients shrunk slightly after the cell therapy, a good sign, whereas the hearts of patients in the placebo group increased in size.
But other researchers at the meeting were cautious about the potential for stem cell therapies for the heart. "We have seen glimpses of success, but we still don't have a consistent approach we would say is the right way to do it," said interventional cardiologist Barry Uretsky of the Sparks Regional Medical Center in Arkansas, who co-chaired the portion of the meeting in which the stem cells results were presented.
The other co-chair, William Knopf, of the Atlanta Cardiology Group, called the stem cell work "an interesting science project" that would need "a lot more time" and much bigger, blinded studies to prove that it worked.
The problem is that there is a bewildering variety of stem cells therapies being used to treat heart problems, using numerous doses, different types of cells, and different methods of delivery into different classes of patients. Most of the trials reported so far have been relatively small, focused mainly on safety. They have measured all sorts of different efficacy parameters, making it difficult to tell which stem cell approach is most promising.
The results of previous stem cells trials for the heart "have been mixed and there have been issues with risk," says Howard Weintraub of the NYU Medical Center, who has not followed details of the Osiris study. He said there needs to be systematic, coordinated studies to determine which type of cells are best, and what type of patients they might work in. "This could be hugely important in medicine, but to let it go forward in a haphazard way would be a mistake."
Dr. Dib of UCSD says he hopes to soon begin a larger trial in 160 heart failure patients in which the thigh-muscle stem cell therapy would be compared in a blinded fashion to a placebo group that got a sham catheter procedure. The trial has been approved by regulators and is expected to begin this year.
Osiris is also looking into to doing more heart stem cells trials, but its first priorities are ongoing final-stage tests of its stem cell therapy in graft versus host disease, and in Crohn�s Disease. "Osiris is in position to commercialize the world�s first stem cell drug,� said C. Randal Mills, chief executive of Osiris.
Cardiologist Marvin Konstam of the New England Medical Center said that cell therapy held "enormous potential" for treating advanced heart disease, but "the big uncertainty is how we are going to get from here to there." Forbes