Phase II study suggests stem cells heal heart, Phase III study starts

Mayo Clinic graphic for regenerative heart story

Healing the human heart, using a patient's own stem cells, may soon evolve from science fiction to medical fact.

A Mayo Clinic discovery has been shown in a Phase II clinical trial to heal heart tissue using patients' own stem cells.

The study participants, who had suffered from heart failure, saw dramatic improvement in qualify of life, said Dr. Andre Terzic, senior study author and director of the Mayo Clinic Center for Regenerative Medicine. One patient, he said, could barely walk before therapy, but has begun riding a bicycle again. Another did not have energy any longer to play the trumpet, but has resumed his musical interest.

The multi-center, randomized " C-CURE" trial included heart-failure patients from Belgium, Switzerland and Serbia.

One study-participant group got standard therapy. The other group got standard therapy plus stem cells harvested from their own bone marrow and pre-treated so they would develop specifically into heart tissue.


"Every patient in the stem-cell treatment group improved," says a Mayo announcement. "Heart pumping function improved in each patient within six months following 'cardiopoietic' stem cell treatment. In addition, patients experienced improved fitness and were able to walk longer distances than before stem cell therapy."

Terzic cautions that study results, published in the Journal of the American College of Cardiology, must be validated with a Phase III clinical trial.

The Phase III trial will enroll about 300 patients in several countries. To become study participants, patients will generally have had a previous heart attack, have stabilized but suffer from heart failure because of damage due to the heart attack. If the Phase III study goes well, researchers would be able to seek regulatory approval to make the therapy available.

Even so, he said, "I think globally this will be very exciting news for patients, and also for their families because heart disease is unfortunately a deadly disease, and once an individual is diagnosed with heart failure essentially the likelihood that individual will survive more than five years is less than 50 percent."

Terzic said researchers were pleased that all patients who were given the stem-cell treatment in the study improved.

A six-minute "walk test" to study fitness, after stem-cell therapy, "they could walk roughly a football field more than patients that did not receive stem-cell therapy. So it's a pretty meaningful improvement."

This is the first study with a patients own stem cells "instructed" to grow into a specific type of tissue and fulfill a specific mission (as optimal a repair of the failing organ as possible), rather than injecting cells and hoping they grow into the right type of tissue.

"This is really a next-generation stem-cell therapy," Terzic said.


The technique to coax a patient's own stem cells to fulfill a specific mission was discovered, developed and "operationalized" in Rochester, he said.

"It took us roughly a decade to do that effort," Terzic said.

His team members, many of whom have been along for the entire decade-long ride, include a man named Atta Behfar, who was a medical student "pinning" Terzic down after class to express interest in regenerative medicine. Behfar, who along with colleagues was critical to Mayo's regenerative-medicine work, is now a fellow in cardiology.

Key to Mayo's discovery of the regenerative-medicine technique was understanding how the human heart normally develops so that the researchers could then try to mimic what happens naturally in a healthy heart.

By understanding that, "we were able to instruct, essentially, stem cells to do it for us in a diseased heart," Terzic said.

He is curious whether the technique can be used with congenital heart problems and perhaps with conditions beyond cardiology, such as neurological disorder treatment, hip repair, wound healing or tendon healing in sports medicine.

Important for patient care, Terzic said, is that the approach used in the Phase II study, since it was used internationally, might be seen as widely doable by health centers worldwide.

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