Safety and Preliminary Efficacy of Allogeneic Endothelial Progenitor Cells (EPCs) in Patients With Critical Limb Ischemia

The purpose of this study is to determine if allogeneic Endothelial Progenitor Cells (EPCs) intravenous infusion to a subject with leg ulcer and/or gangrene due to poor blood flow will be safe and if it will relieve leg pain, increase blood flow, and/or cure the leg wound.

Critical limb ischemia (CLI) is a progressive disease, which arises as a result of atherosclerosis or vasculitis in leg arteries. Prognosis of CLI is poor, and no effective treatments have been established in patients who are not eligible for the traditional revascularization therapies such as angioplasty and bypass procedures due to the inappropriate anatomy of the leg arteries or frequent reocclusion following revascularization. Therefore, it is necessary to establish novel revascularization treatment to improve prognosis of the no-option patients. The investigators will study the safety and clinical efficiency of vascular regeneration by means of transplantation of allogeneic Endothelial Progenitor Cells in patients with CLI who are not eligible for traditional revascularization treatments. The primary endpoint is the safety and tolerance identified by adverse events related with investigated drug；while the secondary endpoints are evaluation of the preliminary efficacy of EPCs.