A trial testing a gene therapy treatment in women who have angina—the piercing chest pain that can trouble the millions of Americans with heart disease—has been given fast-track status by the U.S. Food and Drug Administration.
The study will enroll about 300 women at 50 medical centers in the United States, said Dr. Randall Moreadith, chief medical officer of Cardium Therapeutics Inc., the San Diego company that developed the therapy. The women will receive infusions of a harmless virus engineered to carry a gene that promotes development of new blood vessels. The pain of angina is caused by insufficient blood flow to the heart muscle.
There is an urgent need for a new angina treatment, said Christopher J. Reinhard, chief executive office of Cardium. "These are patients who are getting maximum drug medication, have had bypass surgery and continue to have recurrent angina. They have nowhere else to turn."
Two earlier studies that included both men and women found no overall improvement with the treatment, according to a report in the Sept. 11 issue of the Journal of the American College of Cardiology.
"But when we broke the data down by gender, there was a striking difference in women on exercise treadmill duration," Moreadith said. "Then we saw that every one of the clinical endpoints in women lined up. That was a surprise finding to us."
The treatment uses two technologies developed at different academic institutions—the FGF-4 gene, discovered at New York University, and delivery by infusion through a catheter placed in a blood vessel, developed at the University of California.
The idea of promoting the growth of new blood vessels in the heart "opens a new frontier in the cardiac arena," Reinhard added. Existing treatments for angina are aimed at easing the symptoms of the condition by widening blood vessels, either temporarily with drugs such as nitroglycerin or permanently with procedures such as bypass surgery.
Gene therapy to improve the heart's oxygen supply by inducing development of new blood vessels "deals with the underlying problem," Reinhard explained.
The idea that this therapy could work differently in women makes sense because the physical nature of the condition causing angina is often different in the two sexes, explained Dr. Suzanne Steinbaum, director of women and heart disease at Lenox Hill Hospital in New York City.
In women, diminished blood flow to the heart often is due to general narrowing of many of the arteries feeding the heart, while in men the problem tends to be concentrated in one area, Steinbaum said.
"Women have more diffuse disease, so if you provide more conduits you will have more blood flow and less angina," she said. "With men, the problem is more discrete, so providing more conduits might not relieve symptoms."
"There definitely is something to this that makes sense," Steinbaum said.
Illustration: MicroSoft clipart.
US News & World Report (09/04/07)