This is essay number two in a five part series examining the position that experiments on animals are necessary for life-saving breakthroughs; that without vivisection humans would die.
On 3-25-2011, a letter from Andrew B. Rudczynski, Yale University’s associate vice president for research administration, was published in the New Haven Register. The following is a quote from that letter:
Contrary to claims in a letter to the editor, the basic research model used by Yale University and its peer institutions is scientifically valid and predictive of human disease . . . As an example, Yale neurologist Stephen Strittmatter has discovered mechanisms that allow nerves to repair themselves — promoting promising ideas about therapeutic approaches to repairing damage in patients with spinal cord injuries or have had a stroke. Additional discoveries in his laboratory have defined the molecular events in dementia, providing new avenues for interrupting basic mechanisms of Alzheimer’s disease . . . (Emphasis added.)
There are three problems with this statement and similar statements claiming animal models can predict human response to drugs and disease.
1. By definition, basic research does not seek to predict human response to disease and drugs (see Is the use of sentient animals in basic research justifiable?). Basic research seeks knowledge for knowledge sake and perhaps hopes that this knowledge will someday play a role in decreasing human suffering. Or not. Basic research does not claim predictive ability or even ultimate usefulness to society other than through the notion that all knowledge is useful by definition. A good example of this is the physical sciences like chemistry and physics. When scientists conducted basic research into the physical properties of matter, they were not thinking of inventing the MRI scanner or x-rays. Some of that early basic science research did in fact lead to technologies including MRI and CT scanners but that was not the point of the research. The scientist that conducted such research honestly said to society that they were studying physics and chemistry and electrons or whatever because they thought it was neat and that society would be better off knowing about such thing. No promises of cures for cancer, just knowledge for knowledge sake.
This is what James Hicks, PhD, Professor of Comparative and Evolutionary Physiology at the University of California-Irvine was referring to when he stated:
Every time [the press will] ask me that question, well, what benefit is it [the animal-based research that he doing] for humans? That's the common question. Well, do you ask that of a physicist who's studying black holes?
The answer of course, is: No, society does not ask about the human benefit of studying black holes, but then again physicist do not sell their research to the public promising human benefit vis-à-vis cures for disease. We expect the people performing biomedical research to produce cures because they tell us that they are indeed searching for such cures and that this is why society should fund their studies. We do not expect physicists to find cures because they make no such claims. We expect them to do something that furthers our understanding of black holes or fundamental particles or whatever. Maybe they will even study something for a long time and find out that their hypothesis was wrong. This is acceptable in basic research. This is also one reason why it is difficult to get funding for such research.
2. The concept of prediction in science. As we have written an entire book (see Animal Models in Light of Evolution) and article (Are animal models predictive for humans?) about this and as I blog about this regularly, I will be brief. Animal models cannot and in fact do not predict human response to drugs and disease. Unless you want to say that nonsense like astrology and fortunetelling and psychics can predict the future then you cannot claim that animal models predict human response to drugs and disease. Those who make such claims are: ignorant of what science is; ignorant of how animal models perform in these areas; disingenuous or perhaps some combination of all three.
I am far from alone in this position. The following is from Wenner, writing in Scientific American in 2009:
Seventeen patients had undergone treatment before Gelsinger [the young man who died from a gene therapy procedure in 1999], who was in the final cohort—the one receiving the highest dose of the therapy. Many scientists, as well as the FDA, have raised questions as to why Gelsinger was being treated, given that several patients in earlier cohorts suffered severe liver reactions. Wilson says that they moved forward because it was “the kind of toxicity we would have expected,” based on their work in animals, and they thought it would be manageable. According to Mark Batshaw, director of the Children’s Research Institute at the Children’s National Medical Center in Washington, D.C., Wilson and the rest of the scientific community had to learn the hard way “that what you’ve learned from animals will not necessarily predict what’s going to happen in humans.” Batshaw was also involved in the 1999 trial. (Wenner 2009) (Emphasis added.)
Van der Worp et al 2010:
Animal experiments have contributed much to our understanding of mechanisms of disease, but their value in predicting the effectiveness of treatment strategies in clinical trials has remained controversial [1–3]. In fact, clinical trials are essential because animal studies do not predict with sufficient certainty what will happen in humans. In a review of animal studies published in seven leading scientific journals of high impact, about one-third of the studies translated at the level of human randomised trials, and one-tenth of the interventions, were subsequently approved for use in patients . However, these were studies of high impact (median citation count, 889), and less frequently cited animal research probably has a lower likelihood of translation to the clinic. Depending on one’s perspective, this attrition rate of 90% may be viewed as either a failure or as a success, but it serves to illustrate the magnitude of the difficulties in translation that beset even findings of high impact.
Recent examples of therapies that failed in large randomised clinical trials despite substantial reported benefit in a range of animal studies include enteral probiotics for the prevention of infectious complications of acute pancreatitis, NXY-059 for acute ischemic stroke, and a range of strategies to reduce lethal reperfusion injury in patients with acute myocardial infarction [4–7]. In animal models of acute ischemic stroke, about 500 ‘‘neuroprotective’’ treatment strategies have been reported to improve outcome, but only aspirin and very early intravenous thrombolysis with alteplase (recombinant tissueplasminogen activator) have proved effective in patients, despite numerous clinical trials of other treatment strategies [8,9]. (van der Worp et al. 2010)
Robert Matthews wrote in 2007:
Tests on animals have led to around 100 drugs being thought potentially useful for stroke; not one has proved effective in humans. You don't need to be a balaclava-wearing animal rights activist to question the value of animal studies in this area of medical research. The bigger problem is the belief of the pharmaceutical industry in a myth of its own making. For years it relied on a mix of hard science, inspired guesswork and pure luck to find blockbusters. Many of the most successful drugs have been the result of serendipity.
The above is not new. Alan Oliff, former executive director for cancer research at Merck Research Laboratories stated in 1997: “The fundamental problem in drug discovery for cancer is that the [animal] model systems are not predictive at all” (Gura 1997) and Brodie stated in 1963: “It is often a matter of pure luck that animal experiments lead to clinically useful drugs.” (Brodie 1964)
3. I doubt Stephen Strittmatter’s research (I am not familiar with the research) has resulted in treatments for patients with spinal cord injuries or who have had a stroke but even if this is true it is one instance not a pattern. If a practice is going to be said to be predictive, then the practice must be tested; anecdotes are not sufficient. I can show anecdotes where someone said a very specific event was going to happen in the future and it did. The problem is that the same person also said about one thousand other things were also going to happen and none of them did. A success rate of one out of one thousand and one does not make the practice or endeavor predictive. Furthermore, animal-based researchers and their apologists have been saying things like this for decades: “Just yesterday we discovered something that might lead to something that might lead to a cure for AIDS.” (Substitute for AIDS, the illnesses cancer, stroke, paralysis, or autism depending on what the congressional committee the activist is testifying before on that particular day is interested in.) As we all know, such cures have not materialized despite almost a century of such promises. Claims and promises must be checked against reality.
Using animals to predict human response appeals to common sense and on a superficial level is intuitive. Common sense and intuition however, do not have a good track record in terms of being consistent with the facts of the universe. Science does much better. But science is hard and if something does not “feel right” to people they reject the evidence/data and the conclusions on the basis of those feelings. This is more a reflection of our poor educational system than it is on the utility of acting based on emotion. Our society still values feelings more than science, education, and expertise. When people with a vested interest make claims, society should check very carefully to verify those claims before acting on them.
Clearly, the basis for the vested interest groups claiming that animal experimentation is life-saving is highly questionable. In the next essay, I will discuss the second aspect of the vivisection or death claim: the no other options fallacy.
Brodie, BB. 1964. Of Mice, Microsomes and Man. Acceptance Speech for the Torald Sollmann Award at the Meeting of the American Society for Pharmacology and Experimental Therapeutics, August 13, 1963. The Pharmacologist 6 (1):12-26.
Gura, T. 1997. Cancer Models: Systems for identifying new drugs are often faulty. Science 278 (5340):1041-2.
van der Worp, H. Bart, David W. Howells, Emily S. Sena, Michelle J. Porritt, Sarah Rewell, Victoria O'Collins, and Malcolm R. Macleod. 2010. Can Animal Models of Disease Reliably Inform Human Studies? PLoS Med 7 (3):e1000245.
Wenner, Melinda. 2009. Gene therapy: An Interview with an Unfortunate Pioneer. Lessons learned by James M. Wilson, the scientist behind the first gene therapy death. Scientific American Magazine (September):14.