Gene Therapy Shows Early Promise for Heart Failure
Lab research has suggested that after a heart attack, SDF-1 activity in the heart goes up -- but only for a short time, Penn said. The goal of the experimental therapy is to enhance SDF-1 and draw more stem cells to where they are needed.
The initial results are promising, Penn said. The approach seemed safe, with no major side effects linked to the treatment. Two of the study patients died within a year, but the deaths were deemed not to be connected to the treatment.
Among the 15 patients who were alive one year later, there were improvements in their symptoms and walking ability.
Those gains, however, were "modest," and need to be viewed with some caution, said Dr. Lee Goldberg, medical director of the Heart Failure and Cardiac Transplant Center at the University of Pennsylvania in Philadelphia.
Goldberg pointed out that early studies like this one are set up primarily to see if a therapy is safe, and to figure out what drug dose to use in larger trials -- not to test effectiveness.
"A major limitation of the study is that there was no placebo group," said Goldberg, who also chairs the American College of Cardiology's Heart Failure and Transplant Council. That means there's no way of knowing whether some study patients were showing a "placebo effect" -- the phenomenon where people feel or even function better simply because they believe they received an effective treatment.
Penn said his team is working on a next-stage trial of 90 patients, which will include a group that receives a placebo.
Another cardiologist agreed that the findings on the therapy's benefits have to be "taken with a grain of salt."
"But I do think this seems feasible, and worth studying further," said Dr. David Friedman, chief of heart failure services at North Shore-LIJ's Plainview Hospital, in Plainview, N.Y.
Researchers have long sought to use stem cells to repair diseased hearts, which has included taking stem cells from heart failure patients' bone marrow and infusing them into the heart.
But this new approach, Friedman said, would avoid the steps of harvesting, culturing and reintroducing stem cells into patients. And, according to Penn, it should also be less costly.