ACC: Stem Cell Therapies Hint at Promise for Old and New Heart Attacks

NEW ORLEANS, March 29 -- Investigational non-embryonic stem cell therapies found promise for repairing both new and old cardiac damage, researchers reported here.

Two nearly opposite approaches to using stem cells following myocardial infarction showed safety and suggested efficacy in separate preliminary early phase trials presented at the American College of Cardiology meeting.

"Two very different approaches, both trying to repair heart damage, both show early but quite promising results," said William O'Neill, M.D., of Wayne State University, who moderated a press conference at which the studies were discussed.

In the first study, allogenic mesynchymal stem cells infused following acute MI showed improved pulmonary function and a reduction in arrythmia, said Joshua M. Hare, M.D., of the University of Miami.

The stem cells used in this study, the first clinical use of the approach, were derived from donated bone marrow then grown and amplified such that a single donor yielded about 5,000 off-the-shelf "doses."

"In essence, it's a cell-based drug," Dr. Hare said. The maker, Osiris Therapeutics, is calling the product Provacel.

Dr. Hare and colleagues conducted a phase I dose-escalation study among 53 patients who were randomized to a single dose of stem cells as an infusion up to 10 days after an acute MI or placebo. Doses ranged from 0.5 million cells/kg to 5 million cells/kg.

Patients, ages 21 to 85, had to have an open infarct-related artery on coronary arteriogram, be hemodynamically stable, and an ejection fraction between 30% and 60%.