Safety and Efficacy Study of AVI-5126 When Used on Vein Grafts Before Use in Heart by-Pass Graft Surgery (CABG)

Coronary artery bypass (CABG) is a common procedure employed for life-threatening cardiovascular disease. While bypass surgery is effective in restoring blood flow in the short-term, 30 to 50 percent of venous bypass grafts eventually become blocked or fail. Within the first year after a CABG procedure, it is estimated that between 15 and 30% of saphenous vein grafts fail (i.e., ≥ 75% reduction in flow within the graft), due to intimal hyperplasia at the anastomosis sites. There is currently no approved treatment to prevent venous graft failure. These patients may frequently undergo a second bypass surgery if the extent of graft failure(s) is sufficiently severe to lead to uncontrolled angina pectoris. It is clear that a second CABG procedure in a patient represents a higher operative mortality rate than the first procedure. Venous graft failure in CABG is a major unmet medical-surgical problem. AVI has previously focused some of its Neugene® products in the area of preventing cardiovascular stenosis. This application of antisense targeted to to inhibit the c-myc gene has previously been demonstrated to prevent sequelae of intimal hyperplasia following endovascular injury. The purpose of this study is to evaluate whether immersion of the excised saphenous vein in a novel anti-c-myc antisense drug (AVI-5126) solution will prevent subsequent graft failure at 1 year, compared to physiological saline (placebo) prior to graft anastomosis.