Pluristem Therapeutics said the U.S. Food and Drug Administration has given it clearance to begin an early-stage human clinical trial of its PLX-PAD, the company’s placenta-derived stem cell therapy for the treatment of critical limb ischemia, the end stage of peripheral artery disease.

This will be the first clinical trial using PLX-PAD, an off-the-shelf, one-size-fits-all product that the company says needs no tissue matching prior to being administered to patients. In the early-stage dose ranging trial, to be conducted at multiple locations in the United States, PLX-PAD will be administered to late-stage critical limb ischemia patients who have not responded to traditional medical or surgical interventions.
 
In the United States alone, there are an estimated 8 million to 12 million people who  suffer from critical limb ischemia associated with peripheral artery diseases. The disease is characterized by narrowing and hardening of the arteries in the patient’s limbs, which can be caused or aggravated by diabetes, Buerger’s Disease, other diseases, and smoking.

With decreased blood flow to the affected extremity, patients can suffer a host of complications including nerve and tissue damage. In advanced stages, critical limb ischemia can lead to gangrene, which often requires treatment with amputation. The disease is associated with a high rate of mortality and the need for frequent hospitalization from surgical complications.

Pluristem is working to commercialize unrelated donor-patient or allogeneic cell therapy products for the treatment of several severe degenerative, ischemic, and autoimmune disorders. The company is developing a pipeline of products, stored ready-to-use, that are derived from human placenta. One benefit of this approach is that the placenta provides a non-controversial source of adult stem cells.

Pluristem takes the placenta-derived cells and expands them through the use of a proprietary bioreactor, which imitates the natural microenvironment of these cells and does not require supplemental growth factors or other exogenous materials. Pluristem believes that the resultant cells’ efficacy may be related to the secretion of cytokines or other potent immune modulators. Furthermore, the cells are immune privileged and possess immunomodulatory properties that protect the recipient from immunological reactions that often accompany transplantations.

In addition to peripheral artery disease, the company is developing cell-based therapies for inflammatory bowel disease, multiple sclerosis, bone marrow transplantation, and ischemic stroke.