Safety and Efficacy Study Using Gene Therapy for Critical Limb Ischemia

Inclusion Criteria: * Male or female, between 18 and 90 years of age; * Diagnosis of critical limb ischemia (Rutherford Class 4 or 5), including: * A resting ankle systolic pressure (in either the dorsalis pedis or posterior tibial arteries) of ≤ 70 mmHg in the affected limb; or * A resting toe systolic pressure of ≤ 50 mmHg in the affected limb; or * For patients in which measurement of ankle systolic pressure is not feasible (e.g. vessel calcification and non-compressibility); TcPO2 ≤ 30 mmHg; * Poor or suboptimal candidate for bypass graft surgery or percutaneous angioplasty; * Pain at rest, and/or ischemic ulcers, and/or focal gangrene (\< 3 cm2) for a minimum of 2 weeks, * Significant stenosis (≥ 75%) of one or more of the following arteries: superficial femoral, popliteal, or two or more infra-popliteal arteries as verified by angiography within 12 months prior to enrollment; * Be willing to maintain current drug therapy for peripheral arterial disease throughout the course of the study including an anti-platelet and statin treatment unless not tolerated; * Clinically stable on optimized medical regimen for \>30 days * Be capable of understanding and complying with the protocol and signing the informed consent document prior to being subjected to any study related procedures; * Women who are surgically sterile or at least 1 year postmenopausal or who have been practicing adequate contraception for at least 12 weeks prior to entering the study. If the subject is …