Researchers are poised to begin human clinical trials of a novel gene therapy to treat a major cause of heart disease by shrinking enlarged hearts in order to improve blood flow and cardiac function.
Heart failure, a leading cause of illness and death worldwide, is caused by a weakening and enlarging of the heart as it works harder to pump enough blood to the rest of the body. A heart attack, untreated high blood pressure or clogged coronary arteries can lead to the condition, which kills most people die within five years of diagnosis.
People with heart failure lack a fully functioning gene called SUMO-1, which helps to regulate the calcium that cycles in and out of cells in the ventricles, which pump blood to the body.
In experiments with pigs with heart failure, cardiologist Roger Hajjar at Mount Sinai School of Medicine in New York discovered a single infusion of the gene SUMO-1 dramatically improved the function of the animals’ hearts.
“Regardless of the cause that induced the heart to be big, we were able to reverse that,” he said.
Hajjar's research team at the Cardiovascular Research Center at Icahn School of Medicine has discovered another gene called SERCA2, which also regulates the movement of calcium in heart cells. Their human trials of replacement gene therapy with SERCA2 are showing similar results to the SUMO-1 animal experiments.
Hajjar believes infusing both genes simultaneously into cardiac failure patients might double the benefit.
“Since we’ve had the experience with SERCA2, we know pretty much the path toward clinical trials from discovery to the bedside," he said. "We feel that within a couple of years, we should be able to take this program forward in terms of gene therapy in patients.”
The therapy involving SUMO-1 and SERCA2 uses a harmless cold virus to deliver the genes into the heart.
An article on gene therapy for heart failure is published in the journal Science Translational Medicine