Inflammation and Restenosis
Treatment for Peripheral Artery Disease (PAD)
Mercator’s treatment for PAD, if successful, is aimed at preventing the neointimal hyperplasia that occludes arteries after procedures such as angioplasty, atherectomy and stent placement. The company intends to obtain regulatory approval of one or more compounds for delivery to vessel walls and perivascular tissue through the Micro-Infusion Catheter. Pre-clinical research has shown that Mercator’s formulation of 17b-estradiol delivered with the Micro-Infusion Catheter inhibits up to 75% of the neointimal hyperplasia after an interventional vascular procedure.
PAD affects some 12 million people in the United States. Similar to coronary artery disease, it results from the buildup of fatty plaque and calcification in arteries that restrict blood flow, especially those leading to the kidneys, stomach, brain, arms, legs and feet.
Early symptoms include cramping and fatigue during activities that subside with rest. Symptoms worsen with additional blockage and include skin ulcerations, gangrene, and tissue loss that can culminate in limb amputation. People with PAD often have blocked arteries of the heart and brain. As a result, most people with PAD have an elevated risk of death from heart attack and stroke.
Aging, obesity and diabetes are risk factors for PAD. It is a growing problem in the United States where an estimated 44 million people are obese and 18 million are diabetics. It is estimated that more than 20% of diabetics between the ages of 55 and 74 have PAD. Many PAD patients go untreated, since only 20% with the disease are diagnosed. Experts in the field believe that as PAD awareness improves, diagnosis and treatment will increase.
Current Treatments for PAD
Treatments include angioplasty and stenting to force the artery open, or atherectomy to cut out plaque. Both are effective at opening the artery, but cause injury and can lead to local inflammation, resulting in restenosis and additional procedures to re-open an artery. The post-treatment restenosis rate is approximately 25% after 6 months; another procedure is required within 12 months for up to 40% of treated vessels. Higher long-term success can be achieved if inflammation of the artery wall is reduced.