Pluristem's Off-The-Shelf Placenta-Derived Cell Therapies

Pluristem Press Release, May 20, 2010

Pluristem announced that its "off the shelf" placental stem cells will be the focus of upcoming talking at investor and medical conferences. The company Pluristem is currently in Phase I trials assessing its unique bio-reactor expanded placental stem cells for the treatment of critical limb ischemia. In contrast to other therapies that use the patient's own stem cells (called autologous), the advantage of the "universal donor" or "allogeneic" approach is that large numbers of cells can be generated according to defined conditions. Additionally, universal donor cells can be administered several times at a number that is limited only by the desire of the physician to escalate the dose. In the autologous situation stem cells are usually taken from the bone marrow, making it difficult to perform multiple extractions.

Pluristem will present at the International Society for Cellular Therapy's (ISCT) 16th Annual Meeting in Philadelphia some updates on its ongoing programs.

"We recently reported interim top-line results from our Phase I clinical trials demonstrating that PLX-PAD is safe, well tolerated and had improved the quality of life of CLI patients in the studies," said Zami Aberman, Pluristem's chairman and CEO. "With PLX-PAD, we have the unique opportunity to utilize a single source of cells, the placenta, to treat an unlimited number of CLI patients. Our presentations at the ISCT Annual Meeting and other conferences will highlight the potential of PLX-PAD as well as our core technology that enables the cost-effective development of cell therapies derived from the human placenta."

There are several other companies pursuing "universal donor" stem cells. Medistem, the licensor of technologies used by Cellmedicine has developed such a cell from the endometrium, called "Endometrial Regenerative Cells" that are currently subject of an IND application for use in critical limb ischemia. Athersys is using bone marrow derived universal donor stem cells for treatment of heart failure. The most advancement in this area comes from the company Osiris Therapeutics which also uses bone marrow derived cells to treat a variety of conditions, although all are still in clinical trials.

In the majority of cases universal donor cells are related directly or indirectly to mesenchymal stem cells. These cells, originally discovered by Dr. Arnold Caplan, express low levels of proteins that are seen by the immune system, thus allowing them to be transplanted without matching. Additionally, they also produce proteins that actively suppress the immune system from killing them. In diseases associated with abnormal immunity mesenchymal stem cells have shown promise. Cellmedicine has published on use of mesenchymal stem cells in treatment of multiple sclerosis www.translational-medicine.com/content/pdf/1479-5876-7-29.pdf .