Mr. Chairman, Senator Harkin, and Members of the Subcommittee, I am Dr. Gerald Fischbach, Director of the National Institute of Neurological Disorders and Stroke. I am accompanied by Dr. Allen Spiegel, Director of the National Institute of Diabetes and Digestive and Kidney Diseases. We are before you again to discuss one of the most exciting areas of biomedical research: the enormous potential of human pluripotent stem cells to treat and cure debilitating and deadly diseases.
Only two years ago, researchers discovered and isolated these primordial cells -- whose existence in humans had been theorized but never proven -- the precursors of most of the other cells in the body. Their unique properties of self-renewal and the ability to differentiate into the full spectrum of other cell types make them ideal candidates for repairing and replacing tissues and organs ravaged by disease. New more effective treatments, and maybe even cures, might be developed for juvenile-onset diabetes, Parkinson's Disease, spinal cord injury, ALS or Lou Gehrig's disease, Alzheimer's Disease and many other brain disorders. There is similar potential for the treatment of cancer and heart disease. Virtually every realm of medicine and human health might benefit from this innovation. Stem cell research could alleviate a great deal of human suffering.
Chairman Specter, you and Senator Harkin, in particular, have encouraged the National Institutes of Health (NIH) to invest our resources in stem cell research in order to pursue its enormous opportunities. Patients who are suffering from the most deadly and disabling diseases have also asked that NIH fund this promising arena of research. We believe that federal funding would encourage openness, stimulate more discoveries and translate the promise of this research into practical use more quickly, efficiently, and effectively - and with procedural safeguards.
Recognizing that the ethical issues related to this research required careful consideration, NIH and the Department of Health and Human Services were committed to developing Guidelines to help ensure that pluripotent stem cell research funded by NIH would be conducted in a legal and ethical manner. In drafting the Guidelines, the NIH sought the advice of scientists, patients and patient advocates, ethicists, clinicians, lawyers, the National Bioethics Advisory Commission, and members of Congress. Draft Guidelines were published in the Federal Register last December. The NIH reviewed and considered all comments in preparing the final Guidelines.
We are pleased to inform you that, on August 25, NIH published final Guidelines for research using human pluripotent stem cells. NIH is prepared to begin receiving applications immediately. As soon as the oversight process is in place, NIH will be in a position to fund such research. We expect broad interest from researchers seeking funding for pluripotent stem cell research, and we are hoping to begin funding this research as soon as possible. For procedural reasons, the soonest that awards could likely be made is early next year.
What are stem cells?
Human pluripotent stem cells are a unique scientific and medical resource. They can develop into most of the specialized cells and tissues of the body, such as muscle cells, nerve cells, liver cells, and blood cells, and they are self-renewing, making them readily available for research, and potentially, for treatment purposes. Scientists derived these unique cells from human embryos and from fetal tissue.
Why are human pluripotent stem cells important?
There are three reasons why the isolation of human pluripotent stem cells is so important to science and the future of public health. First, pluripotent stem cells could help us to understand the complex events that occur during human development. Second, human pluripotent stem cell research could also dramatically change the way we develop drugs and test them for safety and efficacy. Rather than evaluating safety and efficacy of a candidate drug in an animal model of a human disease, these drugs could be tested against a human cell line that had been developed to mimic the disease processes. This would not replace whole animal and human testing, but it would streamline the road to discovery, and ensure that only the safest drugs are tested in humans. Third, and perhaps the most far-reaching potential application of human pluripotent stem cells, the generation of cells and tissue could be used for "cell transplantation therapies." Such therapies are aimed at diseases and disorders resulting from the destruction or dysfunction of specific cells and tissue. Although donated organs and tissues can sometimes be used to replace diseased or destroyed tissue, the number of people suffering from such disorders far outstrips the number of organs and tissues available for transplantation. Pluripotent stem cells, stimulated to develop into specialized cells and tissue, offer real hope for the possibility of a renewable source of replacement cells and tissue to treat a myriad of diseases, conditions, and disabilities for which replacement tissue is in short supply. Examples of these include neurological disorders (including spinal cord injuries and ALS), diabetes, burns, heart disease, and arthritis.
Requirements of the Guidelines
The Guidelines prescribe procedures to ensure that NIH-funded research in this important arena is conducted in an ethical and legal manner. They specify the documentation and assurances that must accompany requests for NIH funding for research utilizing human pluripotent stem cells. These Guidelines will encourage openness, help make certain that researchers can make use of these critical research tools, and help assure public access to the practical medical benefits of research using these cells. The Guidelines accomplish these goals in the following ways.
First, the Guidelines help ensure that embryos will not be created for the purpose of deriving human pluripotent stem cells to be used in NIH-supported research. Investigators seeking NIH funds are required to provide documentation that the human pluripotent stem cells were derived from frozen embryos that were created for the purpose of fertility treatment and that were in excess of clinical need. They require a clear separation between the fertility treatment and the decision to donate embryos for this research. In addition, the donation of the human embryos must be made without any restriction regarding the individual who may be the ultimate recipient of the cells for transplantation. Similarly, researchers wishing to use human fetal tissue to derive stem cells must demonstrate that they are in compliance with all applicable laws and regulations. The Federal statute applicable to NIH-funded fetal tissue transplantation research also includes provisions creating a separation between the decision to terminate a pregnancy and the decision to donate fetal tissue for research. Second, the Guidelines ensure that individual choosing to donate embryos cannot receive any inducements, monetary or otherwise. The Guidelines detail specific elements that must be included in the informed consent to help ensure that potential donors receive sufficient information to allow them to decide whether or not to donate human embryos for this type of research. The Guidelines require review and approval by an Institutional Review Board (IRB) to ensure that consent was informed, voluntary, and meaningful.
Third, the Guidelines require accountability on the part of the researcher. Detailed documentation must be submitted to NIH to demonstrate compliance. For example, the grantee institution must sign an assurance that the research to be conducted is in compliance with the Guidelines, and that the institution will maintain documentation to support the assurance. The researcher/grantee institution must submit a sample informed consent document, with patient identifier information removed, a description of the informed consent process, and documentation of IRB review.
Fourth, the Guidelines specify types of research that the NIH will not fund. For example, NIH will not fund any research that seeks to derive pluripotent stem cells from human embryos, research utilizing pluripotent stem cells that were derived from human embryos created for research purposes, or any research that seeks to derive or utilize stem cells from embryos that were created using somatic cell nuclear transfer (cloning technology). Fifth, the NIH has designed an oversight process that will provide an extra level of protection, above and beyond standard peer review of grant applications, to ensure that researchers have complied with the Guidelines. A newly-created NIH working group called the Human Pluripotent Stem Cell Review Group (HPSCRG) will review documentation submitted by researchers demonstrating that they are in compliance with the Guidelines. Members of the HPSCRG will subsequently make recommendations to its parent committee, the Center for Scientific Review Advisory Committee. NIH will not fund research or allow existing funds to be used for research using human pluripotent stem cells derived from human embryos or human fetal tissue until the required compliance documentation receives HPSCRG review and approval of the NIH Center for Scientific Review Advisory Committee. Continued compliance with the Guidelines will be a term and condition of the NIH award.
Human Pluripotent Stem Cells and Diabetes Research
One of the best examples of the promise of this line of research is in the treatment of Type 1 diabetes. Research on islet cell transplantation and stem-cell biology offers compelling opportunities for the development of new, innovative approaches for treating and ultimately curing this disease. Type 1 diabetes, often referred to as juvenile diabetes, is characterized by the inability of the body to produce insulin, a hormone necessary for glucose metabolism. This form of diabetes occurs when the body's immune system attacks and destroys its own insulin-producing islet cells in the pancreas. As a result of inadequate insulin production, glucose does not enter cells as readily as when insulin levels are normal. The standard treatment is to try to control the glucose level with insulin injections.
Transplantation of insulin-producing islet cells is an alternative approach to controlling glucose levels. In a recent study, seven patients receiving islet transplants became completely independent of the need for insulin injections. NIH is currently funding a multi-center trial of the protocol used in this study to determine if the same success can be achieved in a larger number of patients. A successful outcome to this trial, as exciting as it would be for patients with Type 1 diabetes, will only serve to underscore the limitation in the supply of islets available for transplantation compared to demand. While many approaches to address the islet supply problem, including work on cell bioengineering and adult stem cells are being vigorously pursued, human pluripotent stem cells offer the greatest promise of providing a limitless source of islet cells for treating and curing Type 1 diabetes.
Human Pluripotent Stem Cell Research and the Nervous System
As significant as the promise of stem cells is for the treatment of diabetes, the potential of stem cells for treating diseases of the nervous system is equally impressive. The most obvious and exciting use of stem cells in neurological disorders is to replace nerve cells lost to disease or injury. Many diseases destroy particular types of nerve cells, and mature nerve cells cannot produce new cells to replace those that are lost. Animal experiments have demonstrated that the potential exists for coaxing stem cells to specialize and replace the dopamine cells that are lost in the brain through Parkinson's disease. A similar approach might also apply to several other neurological disorders. Human pluripotent stem cells, given appropriate control signals, might specialize to replace the lost acetylcholine producing nerve cells in Alzheimer's disease, to restore lost motor neurons in ALS, or to produce inhibitory cells to help restrain electrical activity in epilepsy.
Replacing lost nerve cells is only the beginning of the list of possible therapeutic applications for stem cells. For some disorders, such as multiple sclerosis, stem cells might replace supporting cells, such as the glial cells, which provide the insulation necessary to allow some nerves to conduct electrical impulses rapidly. In addition to their potential in replacement therapy, stem cells can provided nutritive factors that might prevent the loss of nerve cells in the first place. Stem cell strategies might be useful for correcting inherited defects. For example, in disorders that devastate children's brains, we might rely on the ability of stem cells to migrate widely in the brain and supply the vital missing enzyme that leads to early and tragic death from Tay-Sach's disease. In addition, stem cells might regenerate the many different kinds of complex brain tissue that are damaged as a result of brain trauma or stroke. Transplanted stem cells might also supply natural growth and survival chemicals to pave the way for regeneration of remaining healthy neural tissue following spinal cord injury. Recent findings suggest that stem cells might be harnessed to seek out and destroy brain tumor cells that evade surgery or radiotherapy. The list of possible applications of stem cells continues to grow as we learn more about these cells.
Mr. Chairman, we appreciate the opportunity to discuss this promising and extraordinary science and are pleased to respond to any questions you may have.
Last Modified December 29, 2010