Mending More Than Hearts
The company just completed a Phase I study and is starting a Phase II trial of fibroblast growth factor in coronary heart disease. Angiography reveals that, in just 12 weeks, fibroblast growth factor injected close to clogged blood vessels induces the formation of new blood vessels and capillaries. Once blood flow is established through the sprouting of new blood vessels that bypass the damage site, patients with cardiovascular disease experience an increase in life expectancy and quality of life.
CVBT is also evaluating fibroblast growth factor in peripheral artery disease. When atherosclerotic lesions block blood vessels in the legs, it becomes painful to walk, a condition called intermittent claudication. Circulation to the foot and leg can become so reduced that amputation is needed.
“If left untreated, peripheral artery disease increases the risk of heart attack, stroke, amputation, or death,” says Dr. Stegmann. The multicenter Phase I trial will treat patients with intermittent claudication with injections of fibroblast growth factor. Patients’ legs will be evaluated before and after treatment with MRI to quantify changes in blood flow.
In another Phase I trial, fibroblast growth factor formulated as a cream will be applied externally to treat wound, such as diabetic ulcers. “Chronic wounds often never heal because they need perfusion, an arterial blood supply, and oxygen,” Dr. Stegmann explains.
Also, a proof-of-concept study conducted in Russia will study patients with chronic back pain caused by degenerative disc disease. Many of these patients have atherosclerosis of the lumbar arteries that nourish back muscle and tissue. “Some orthopedic surgeons believe that degenerative disc disease is an ischemic condition,” Dr. Stegmann says. Patients whose angiograms show occluded or calcified lumbar arteries will be injected with fibroblast growth factor to regenerate blood vessels.
A similar feasibility study will take place at the Orthopedic Education and Research Institute of Southern California in Orange, coordinated by orthopedic surgeon Vance Gardner, executive director of the facility.
In the near future, Dr. Stegmann plans to use fibroblast growth factor to treat stroke. Animal experiments indicate that angiogenesis could repair the damage done to blood vessels by blood clots during a stroke. However, before starting a Phase I trial in stroke patients, “we want to advance our studies in other conditions first,” Dr. Stegmann adds.
In all of these medical conditions being treated, fibroblast growth factor works the same way. The protein stimulates the growth and multiplication of two main cell types found in blood vessels—smooth muscle and endothelial cells. Receptors in hypoxic cells are sensitive to fibroblast growth factor, which promotes angiogenesis locally.