Safety Study of Adult Stem Cells to Treat Patients With Severe Leg Artery Disease (SCRIPT-CLI)

Peripheral artery disease (PAD) due to leg artery blockages can result in painful leg muscles, skin ulcers and infection due to poor blood flow. In severe forms, the only treatment may be amputation. Adult stem cells injected into affected legs may cause new blood vessel formation and improve blood flow. The purpose of this study is to determine the feasibility and safety of injecting adult stem cells into the leg muscles of patients with severe PAD, in an attempt to improve blood flow.

Lower extremity peripheral artery disease (PAD) is a common, debilitating and potentially life-threatening illness. Obstructive PAD can progress to limb-threatening ischemia with rest pain, ulcers, and gangrene requiring amputation unless blood flow to the ischemic limb can be restored. Surgical revascularization options are often limited by arteries that are too small to bypass. Patient co-morbidities also make surgical options risky. Percutaneous revascularization techniques are similarly limited by small distal artery caliber, technical difficulty and high restenosis rates. Amputation may be the only treatment option for non-healing ulcers or gangrene. Direct intramuscular injection of adult stem cells may result in improved lower extremity perfusion, symptomatic improvement and limb salvage in patients with critical limb ischemia not optimal for conventional revascularization. This study aims to demonstrate the safety and feasibility of this therapeutic approach.

Inclusion Criteria: Ambulatory critical limb ischemia (Rutherford Score 4/5) Not optimal for surgical or catheter-based revascularization Obstructive atherosclerosis of at least 1 major artery in both limbs Ankle-Brachial Index <0.6 or Absolute Ankle pressure <60mmHg or toe pressure <40mmHg or pulse volume recording that is flat or barely pulsatile Exclusion Criteria: Gangrene(Rutherford 6) or pre-existing major tissue loss Unstable Angina, MI, stroke, CHF (class III or IV) within 6 months of study treatment

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