Study to Evaluate the Safety and Efficacy of JVS-100 Administered to Adults With Critical Limb Ischemia

48 subjects diagnosed with Rutherford Class 4-5 Critical Limb Ischemia (CLI) with non-healing ulcers and/or ischemic rest pain will be enrolled in this study designed to investigate the safety and efficacy of JVS-100. JVS-100 will be delivered by direct intramuscular injection into the limbs of study subjects. Subjects will be randomized to receive a single set of direct intramuscular injections of either JVS-100 or vehicle control and will be followed for 12 months post dosing. Safety and efficacy assessments will be collected at 3 days, 4 weeks and 3, 6 and 12 months.