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Promising results using VEGF in the treatment of coronary artery disease:
Gene therapy shows promise in U.S. heart patients
By Maggie Fox, Health and Science Correspondent
WASHINGTON, Jan 26 (Reuters) - Doctors reported more progress in using gene therapy to treat heart disease on Tuesday, saying 19 out of 20 patients they tried it on reported less chest pain.
The team at St. Elizabeth's Hospital at Tufts University in Boston said the patients grew tiny new blood vessels on the surfaces of their hearts after having new genes injected directly into their hearts.
Dr. James Symes, a heart surgeon at St. Elizabeth's, and colleagues injected a compound containing a gene known as VEGF.
"What we think is happening is that the gene produces the VEGF protein, which we know stimulates new blood vessel formation, and it presumably causes those blood vessels to grow and supply blood from the part of the heart that's got enough blood to the part of the heart that doesn't," Symes said in a telephone interview.
"So it's an inside-the-heart bypass."
The same team had reported earlier success with the VEGF gene, which stands for vascular endothelial growth factor.
In November, they said 16 patients had safely undergone the procedure, and they added another four since. "We are now up to 20 patients who had completed 60 days," Symes said.
The 15 men and four of five women said their angina or chest pain -- which indicates blockages in the blood supply to and from the heart -- diminished afterwards.
All the patients had undergone either heart bypass operations -- several for most -- or another procedure to get blood flow to the heart.
"All patients followed to Day 60 reported a reduction in angina," the researchers wrote in a report to be presented at the annual meeting of the Society of Thoracic Surgeons in San Antonio, Texas. "Seventy percent of patients were completely angina-free at six months."
One woman died of pneumonia four months after her operation, a complication of the surgery but not of the gene therapy itself, Symes said.
The researchers said all 20 patients had been considered nearly hard cases because previous operations had failed.
They all had multiple reasons for heart disease -- 13 were smokers, 19 had high blood pressure, nine had diabetes, 18 had high cholesterol, five had blockages in their legs and eight had suffered strokes.
All had, before the operation, suffered chest pain every day and were taking nitroglycerin for it. They were also taking other heart disease drugs, including beta-blockers, calcium channel blockers, aspirin and cholesterol-lowering drugs.
About 250,000 patients a year with ischemia, or blocked blood flow, cannot be helped by bypass surgery, angioplasty to stretch open the vessels, or drugs.
Perfusion scans -- nuclear scans done on heart patients to measure blood flow -- showed improvement in 13 of the 20 patients, Symes said. "Probably out of the 17 patients that had a nuclear study done at 60 days, 13 had shown improvement in the scan," he said.
Symes said it was far too early to tell whether the gene therapy could become routine. He noted that the patients were getting some blood through their bypasses, just not enough, and it was not clear whether the amount of blood flowing through the new capillaries would be enough on its own without a bypass.
It is also not clear how long the new blood vessels will last.
"We don't want people to get the impression that this is a proven therapy that they should be signing up for until we have done more work," Symes said. "But it is going in the right direction, no question."
Human Genome Sciences Inc. <HGSI.O> has licensed the right to develop VEGF to Vascular Genetics Inc., a company that HGSI formed with St. Elizabeth's.
03:13 01-27-99
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