In this research study an investigational product called PLX-PAD will be tested to see if it helps claudication. PLX-PAD is made up of mesenchymal-like stromal cells (MSCs), which are similar to stem cells. These cells come from a human placenta (afterbirth) from chosen female donor volunteers. From animal experiments it is known that PLX-PAD cells can have a helpful effect on the blood circulation. The purpose of this research study is to test whether PLX-PAD is safe and see how well PLX-PAD works compared to placebo (inactive substance that contains no study product). Subjects will receive the assigned treatment twice to the affected leg, with a 12-weeks interval between each treatment. The study will be comprised of 5 stages: 1. Screening period of up to 4 weeks 2. First treatment of PLX-PAD or placebo followed by 1 hour of monitoring at week 0 3. Short-term follow-up at weeks 1, 4 and 12 after first treatment 4. Repeat dose of PLX-PAD or placebo at week 12 after first treatment 5. Long-term follow-up at weeks 13, 26, 39 and 52 after first treatment. Study termination at week 65 after first treatment. Approximately 150 subjects will be enrolled into this study in order to have 126 subjects completing the study. A target number of 44 subjects will be enrolled into each of the 2 x high dose and 2 x placebo groups (groups 2 and 3) and 31 subjects will be enrolled into each of the 2 x low dose and high dose plus placebo groups (groups 1 and 4). The expected duration of study participation for each subject is 65 weeks.

You may be eligible for this study if you meet the following criteria:

• Conditions: Intermittent Claudication, Peripheral Arterial Disease
• Age: 1 years - 99 years
• Gender: All