Science did a very nasty and, in my view, politically motivated thing before the election: It printed a hit piece by William Neaves and others against David Prentice, essentially accusing him of lying to the public, without giving him a chance to respond. Finally, half a year later, they deigned to permit Prentice to respond. Here is his letter in its entirety:
Treating Diseases with Adult Stem Cells
Letters Science 19 January 2007: Vol. 315. no. 5810, p. 328
In their Letter “Adult stem cell treatments for diseases?” (28 July 2006, p. 439), S. Smith et al. claim that we misrepresent a list of adult stem cell treatments benefiting patients (1). But it is the Letter’s authors who misrepresent our statements and the published literature, dismissing as irrelevant the many scientists and patients who have shown the benefits of adult stem cells.
We have stated that adult stem cell applications have “helped,” “benefited,” and “improved” patient conditions. Smith et al.’s Supporting Online Material (2) repeatedly notes patient improvement from these cells (3). We have never stated that these treatments are “generally available,” “cures,” or “fully tested in all required phases of clinical trials and approved by the U.S. Food and Drug Administration (FDA).” Some studies do not require prior FDA approval (4), and even the nine supposedly “fully approved” treatments acknowledged by Smith et al. would not be considered “cures” or “generally available” to the public at this stage of research.
The insistence that no benefit is real until after FDA approval is misplaced. Such approval is not a medical standard to evaluate patient benefit, but an agency determination that benefits outweigh risks in a broad class of patients. Physicians and patients use an evidentiary standard. Our list of 72 applications, compiled from peer-reviewed articles, documents observable and measurable benefit to patients, a necessary step toward formal FDA approval and what is expected of new, cutting-edge medical applications.
Smith et al. also mislead regarding citations for testicular cancer and non-Hodgkin’s lymphoma, referring to “[t]he reference Prentice cites,” as though only one reference existed in each case, and not mentioning four other references that, according to their own SOM, show “improved long-term survival” of patients receiving adult stem cells. There are currently 1238 FDA-approved clinical trials related to adult stem cells,including at least 5 trials regarding testicular cancer and over 24 trials with non-Hodgkin’s lymphoma (5). They also disregard studies showing successful stimulation of endogenous cells for Parkinson’s.
The ethical and political controversy surrounding embryonic stem cell research makes scientific claims especially prone to exaggeration or distortion. All such claims should receive careful scrutiny, as recently acknowledged by the editors of this journal after two articles claiming human “therapeutic cloning” success were revealed to be fraudulent. This scrutiny should be directed equally to all sides. We note that two of our critics, Neaves and Teitelbaum, are founding members of a political group whose Web site lists over 70 conditions that “could someday be treated or cured” using embryonic stem cells (6). High on this list is Alzheimer’s disease, acknowledged by experts as a “very unlikely” candidate for stem cell treatments, with one NIH expert describing such a scenario as a “fairy tale” (7). The entire list, in fact, is based on no evidence of benefit in any human patient from embryonic stem cells and little evidence for its claims in animal models. No one should promote the falsehood that embryonic stem cell cures are imminent, for this cruelly deceives patients and the public (8).
David A. Prentice*