WASHINGTON (BP)–The U.S. Food and Drug Administration’s postponement of a human trial using embryonic stem cells resulted from the development of cysts in animals undergoing tests.
The Geron Corp. acknowledged the reason for the delay in an Aug. 27 news release, saying cysts had developed at the injury sites in lab animals. The Menlo Park, Calif., biotechnology firm announced Aug. 18 the Food and Drug Administration had placed a hold on the proposed trial on human beings with spinal cord injuries but did not provide details regarding the reason for the postponement.
Geron received the FDA’s permission in January to proceed with the first U.S. embryonic stem cell experiments in human beings. At the time, the company announced its plan to inject embryonic stem cells at the point of damage in as many as 10 paralyzed patients. The injections would occur within 14 days of the patients’ spinal cords being injured.
Pro-life advocates and others oppose embryonic stem cell research (ESCR) based on what it does to donor embryos and potentially to patients. ESCR’s drawbacks include:
— Extracting stem cells from an embryo destroys the tiny human being.
— ESCR, unlike trials with adult stem cells, has yet to produce any therapies in human beings.
— It has been plagued by the development of tumors in lab animals.
Southern Baptist bioethicist C. Ben Mitchell said the FDA hold on Geron’s trial “shows once again that not only is it unethical to destroy embryos for their stem cells” but ESCR “results in serious worries about safety.”
“To conduct human trials would be morally unconscionable,” said Mitchell, Graves professor of moral philosophy at Union University in Jackson, Tenn., and a consultant to the Ethics & Religious Liberty Commission.
In its Aug. 27 announcement, Geron said earlier experiments with animals showed a “very low frequency of injected animals developed microscopic cysts” at the injury site. The cysts did not proliferate, were limited to the injury site and did not affect the animals negatively, according to Geron. Also, no teratomas, which are tumors that may or may not be malignant, developed in the animals.
Geron reported, however, a “just completed animal study showed a higher frequency of cysts.” Another recently finished animal trial did not produce any cysts, according to Geron.
The firm is cooperating with the FDA in an effort to begin the human trial, Geron said.
Because of their ability to develop into other cells and tissues, stem cells provide hope for producing cures for a variety of diseases. The biotech industry has long promoted research with embryonic stem cells because of their pluripotency, which means they can transform into any cell or tissue. ESCR has not proven nearly as effective as experiments with other types of stem cells, however.
Trials using adult stem cells have produced therapies for at least 73 ailments in human beings, despite the fact such cells are not considered pluripotent, according to Do No Harm, a coalition promoting ethics in research. Among the afflictions treated by adult stem cells are cancer, juvenile diabetes, multiple sclerosis, heart damage, Parkinson’s, sickle cell anemia and spinal cord injuries, according to Do No Harm.
Scientists have discovered induced pluripotent stem (iPS) cells in the last two years, producing great promise for cures without the ethical problems of ESCR. In iPS research, scientists convert adult cells into cells that have nearly the identical properties of embryonic ones.
Neither procuring stem cells from non-embryonic sources nor transforming adult stem cells into embryonic-like ones harms the donor.
Since the FDA gave Geron the go-ahead to conduct a human trial with embryonic stem cells, President Obama has overturned a ban on federal grants for stem cell research that results in the destruction of an embryo. President Bush issued the ban in 2001, but he permitted funds for experiments with stem cell lines, or colonies, already in existence at the time of his order.
At the time the FDA approved a human trial with embryonic stem cells, the lines used by Geron were eligible for federal money, according to the Associated Press.
Guidelines issued by the National Institutes of Health in July limit federal funds to research involving embryos produced by in vitro fertilization for reproductive purposes and donated by couples who no longer want them. The couples must provide voluntary, written permission.
A suit filed Aug. 19 in federal court contends the guidelines violate a 13-year-old congressional ban on funds for research that destroys embryos. The plaintiffs say the guidelines violate the 1996 Dickey-Wicker Amendment, a rider to the spending bill for the Department of Health and Human Services. The amendment prohibits federal funds for “(1) the creation of a human embryo or embryos for research purposes; or (2) research in which a human embryo or embryos are destroyed, discarded, or knowingly subjected to risk of injury or death greater than that allowed for research on fetuses in utero….”
Compiled by Baptist Press Washington bureau chief Tom Strode.