Legs May Provide Stem Cells for Failing Hearts
International trial set to test procedure
FRIDAY, Feb. 7, 2003 (HealthDayNews) -- An international experiment to rebuild failing hearts using stem cell implants is under way, researchers report.
The trial will enroll up to 300 patients in as many as 30 medical centers in the United States and Europe. The idea is to strengthen failing heart muscle by removing stem cells from the patient, growing them in the laboratory, and then injecting them into a scarred region of the heart during surgery so they can grow into healthy heart muscle.
The technique was pioneered in France, and physicians at the George Pompidou European Hospital in Paris now report in the Feb. 8 issue of The Lancet on the first patient to receive an implant. The patient, a 72-year-old man, had marked improvement of heart function until his death 18 months later of causes unrelated to the implant, the report says.
The implanted cells were taken from stem cells of the muscles that support the bones. However, stem cells can grow into cells of different tissues, depending on their surroundings.
A biopsy showed the implanted stem cells formed functioning heart tissue, says Dr. Albert A. Hagege, a member of the research team and lead author of the journal report. "This is the first demonstration of the concept in humans and confirms animal experiments," he says.
Since then, the procedure has been performed on 10 patients in France in a Phase 1 trial, the first of three steps required to gain U.S. Food and Drug Administration (FDA) approval for wide-scale use, Hagege says. "This trial supports the feasibility and safety of the procedure," he adds.
The American branch of the study, a Phase 2 trial in the process aimed at FDA approval, will be done in collaboration with the Genzyme Corp., a Massachusetts-based biotechnology company, Hagege says. Selection of patients has already begun in Europe and will begin "in the coming months" in the United States, says Daniel Quinn, a Genzyme spokesman.
Candidates for the treatment will be people whose hearts are beginning to fail because of a heart attack, Quinn says, with the implant aimed at "stopping the progression to heart failure." Because the cells must be injected directly into the heart, the procedure will be done during bypass surgery, he says. Research aimed at allowing the cells to be put in the heart without surgery is under way, Quinn says.
In practice, the stem cells will be removed from a patient through a small biopsy in the leg two to three weeks before bypass surgery is scheduled, and they will be multiplied in laboratory cultures in the Genzyme facility for about three weeks. After that, they will be injected into a scarred region of the heart. This will be a scientifically controlled study, meaning that some patients will get the stem cell implant and others will get a dummy injection. The condition of all the patients will be monitored continually to see whether those getting the real implant do better than those getting the dummy injection.
"The results of the Phase 2 study will probably be available within two to three years," Quinn says. If the trial is successful, a Phase 3 trial aimed at final FDA approval will be done.