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【出版时间及名称】：2010年3月全球干细胞行业研究报告
【作者】：NATIONAL SECURITIE
【文件格式】：pdf
【页数】：52
【目录或简介】：
The Promise of Stem Cells
Stem cells can transform into the dazzling array of specialized cells that make us what we are. Some of the most serious medical conditions, such as cancer and birth defects, are due to problems that occur somewhere in this process. The holy grail of stem cell therapy is to cure diseases with a one-time transplant of cells which replace damaged or defective organs. Today, donated organs and tissues are often used to replace those that are diseased or injured. Unfortunately, the number of people needing a transplant far exceeds the number of organs available for transplantation. Pluripotent stem cells offer the possibility of a renewable source of replacement cells and tissues to treat a myriad of diseases and/or injuries, including Alzheimer’s and Parkinson's Diseases, amyotrophic lateral sclerosis, spinal cord injury, heart disease, liver disease, diabetes, arthritis and burns.
In order to realize the promise of stem cells in regenerative medicine, major ethical, scientific, regulatory and commercial challenges must be overcome. On the ethical front, the dilemma related to embryo destruction has been largely overcome by the discovery and development of adult stem cells. On the scientific side, there are several key questions: Can the cells do what they are required to do? Can they engraft, integrate and restore function? Will immune suppression be required to prevent rejection? From a regulatory perspective, what are the specific hurdles to be overcome in order to show safety and efficacy as a therapeutic product? Embryonic stem cell-derived products must also address the risk of teratogenicity. Cells intended for transplant face higher safety hurdles than cells that don’t engraft and are cleared by the patient’s body once their mission is accomplished. On the commercial side, which model will prevail: Cells available “off the shelf” or personalized cell therapies delivered in a service model? Can manufacturing economies of scale be achieved? Finally, will intellectual property rights create barriers?
Companies have taken various routes to address these issues. StemCells is addressing the challenges of transplant, engraftment, tissue integration and function in its trial of neuronal stem cells transplanted into the brains of children with certain fatal neurodegenerative disorders. Companies such as Athersys, Pluristem and Aastrom, on the other hand, use stem cells to alter the microenvironment, allowing damaged host tissue to heal itself. There is no engraftment or integration. Immune recognition is avoided because these stem cells appear to downregulate the inflammatory responses of the immune system and thereby avoid rejection. Autologous cells used by Aastrom and other companies also avoid rejection. On the regulatory front, many companies are conducting trials to demonstrate the efficacy and safety of their stem cells. Aastrom recently announced positive interim data from a Phase 2b trial in critical limb ischemia, but Osiris did not meet the endpoints in its Phase 3 trial in graft-vs.-host-disease. Geron’s trial of embryonic stem cells for spinal cord injury is on hold because the appearance of cysts has stoked fears of teratoma formation, a property of embryonic stem cells. On the commercial side too, different approaches have evolved. Athersys and Pluristem have developed industrial scale manufacturing processes capable of producing many doses of stem cells from a single donation, whereas Aastrom collects each patient’s cells for personalized therapy. Still others like NeoStem, CryoCell and Thermogenesis have developed a service model in which an individual’s cells are collected and banked for future use.
Investors have largely ignored the stem cell space because the technical challenges have seemed insurmountable. However, we would compare the stem cell arena today to the field of monoclonal antibodies a few years ago. Initial excitement at the discovery of monoclonal antibodies soon gave way to disappointment because of hurdles such as immune rejection of mouse-derived antibodies. However, scientific advancements, including humanization and phage display, were able to circumvent these problems. Today, several billion dollar blockbuster antibodies are on the market and almost 200 monoclonal antibodies are in development for a wide variety of diseases (PhRMA 2008 report: Medicines in Development, Biotechnology). In a similar manner, we expect advancements in stem cell science to lead to dramatic breakthroughs.
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