Study of HGF Via Plasmid Vector to Improve Perfusion in Critical Limb Ischemia

Inclusion Criteria: * Subjects will have one or more clinical indications diagnostic of CLI such as: distal extremity pain at rest that requires the subject to use analgesics for \>2 weeks; or peripheral ischemic ulcer(s); or areas of gangrene. * The subject will have a TcPO2 of \</= 40 mmHg. * Subjects will have one or both of the following hemodynamic indicators of severe peripheral arterial occlusive disease: (a) Ankle systolic pressure of \</= 70 mmHg; (b)Toe systolic pressure \</= 50 mmHg. * The subject is a poor candidate for standard revascularization treatment options for peripheral arterial disease, based on inadequate bypass conduit, unfavorable anatomy, or poor operative risk. * Subject has signed an informed consent form either directly or through a legally authorized representative * If female, the subject must be (a) at least one year post-menopausal, or (b) surgically sterile, or (c) if the subject is of child-bearing potential, she must have been practicing contraception for at least 12 weeks prior to entering the study. * If subject is of reproductive potential, he or she must be using an accepted and effective (barrier) form of birth control during the study. * Subjects will be on a statin and an anti-platelet agent as part of their standard of care and must be stable on these regimens for at least 4 weeks prior to treatment. Exclusion Criteria: * Subjects, who in the opinion of the investigator, have a vascular disease prognosis that indicates they would require a major amputation (at or above the ankle) within 4 weeks of start of treatment. * Subjects with a diagnosis of Buerger's disease (Thromboangitis Obliterans). * Subjects with hemodynamically significant aorto-iliac occlusive disease. * Subjects who have had a revascularization procedure within 12 weeks prior to treatment initiation that remains patent. Revascularization procedures that are evidenced to have failed for \>2 weeks prior to treatment initiation are acceptable. * Subjects who require a change in their hypertension medication as part of their standard of care within 4 weeks prior to treatment. * Evidence or history of malignant neoplasm (clinical, laboratory or imaging), except for basal cell carcinoma of the skin. * Subjects who have proliferative diabetic retinopathy or severe, non-proliferative retinopathy * Subjects with end stage renal disease (ESRD) defined as significant renal dysfunction evidenced by a creatinine of \> 2.5, or receiving chronic hemodialysis therapy. * A subject who has hepatic cirrhosis, viral hepatitis, or is HIV positive. * Subjects with a clinically significant liver enzyme abnormality (i.e., AST or ALT more than two times the upper limit of normal and/or bilirubin more than 50% the upper limit of normal). * Subjects requiring the use of hyperbaric oxygen treatment for wound healing during the screening and 6 month follow-up period.