FDA Postpones First U.S. Clinical Trial of Embryonic Stem Cells

New York Times, May 15, 2008

On April 10, 2008, the U.S. Food and Drug Administration (FDA) convened a panel of experts to examine the safety concerns associated with the use of embryonic stem cells in human clinical trials, in response to applications that were submitted by three companies, namely, Geron, Advanced Cell Technology, and Novocell. Consequently, the FDA issued a strong cautionary statement on the dangers of embryonic stem cells, although the three companies continued with their plans to commence clinical trials in the summer of 2008.

Yesterday, however, the company Geron received an oral notification from the FDA of a delay in the approval process that is required before clinical trials may begin. Based in Menlo Park, California, Geron had planned to begin human clinical trials for the treatment of acute spinal cord injuries in which they would test their proprietary compound made with human embryonic stem cells. Geron is now awaiting a formal letter of explanation from the federal regulators at the FDA.

According to Thomas B. Okarma, Geron's CEO, "We are disappointed with this action given the interactions we had with the FDA over 3 years leading to the filing", which consisted of an application that was 21,000 pages in length. According to Ren Benjamin, an analyst with the investment bank Rodman & Renshaw, Wall Street is not surprised by the FDA's action which analysts regard merely as causing a temporary delay in, rather than a final end to, the clinical trial plans.

The panel of experts that was convened by the FDA in their April 10th meeting stressed the importance of stringent safety measures in embryonic stem cell trials. According to Dr. Steven Bauer, Acting Chief of the FDA's Office of Cellular, Tissue and Gene Therapies, a branch of the Center for Biologics Evaluation and Research (CBER), the agency is likely to require "particularly strong" evidence to substantiate claims of embryonic stem cell safety and efficacy. Assuming that the clinical trials will be allowed to begin, the FDA may also require longer trials than those that are required for the approval of conventional drugs.

It is a well-established fact that embryonic stem cells cause the formation of a specific type of cancerous tumor known as a teratoma; indeed, such a feature of embryonic stem cells constitutes their defining trait. An embryonic stem cell is a cell which, by definition, forms a teratoma, and this remains the universal laboratory test by which embryonic stem cells are identified throughout the world. This test is the global scientific standard of measurement: if a cell forms a teratoma, then it is recognized as being an embryonic stem cell; if a cell does not form a teratoma, then it is recognized as being just an ordinary adult stem cell or some other type of cell. Adult stem cells, by stark contrast to embryonic stem cells, carry no such risk for the formation of teratomas. These facts are well known and well understood throughout the scientific community, and always have been, although they are not often reported to the general public by the media.

Ever since 1999, when an 18-year-old patient named Jesse Gelsinger died four days after receiving experimental gene therapy in a clinical trial, FDA regulators have been particularly sensitive to potential risks that may be associated with clinical trials, and justifiably so. Any further undesirable medical conditions that may result from clinical trials would not only constitute personal tragedies for the individuals involved, but such consequences would also constitute severe policy setbacks for the entire FDA approval process as a whole. Currently, with human embryonic stem cells, the dangers are already well documented and no successes to date have ever been reported or published. Thus far, human embryonic stem cells have never been used to treat any human disease or injury, precisely because human embryonic stem cells have proven to be so highly problematic in the laboratory. By dramatic contrast, however, adult stem cells are already being used in numerous clinics around the world to treat a wide variety of diseases and injuries, efficaciously and in most cases without any side effects.

Dispite the cautionary delay by the FDA, Geron, as well as Advanced Cell Technology and Novocell, are still planning to be able to begin human clinical trials with their proprietary embryonic stem cell compounds.