Toxicology For the Twenty-First Century
An Animal Rights Article from All-Creatures.org

FROM

National Anti-Vivisection Society (NAVS)
By Ray Greek, MD of Americans for Medical Advancement
September 2009

Dr. Greek takes an in-depth look at the 3Rs

Using animals in toxicity testing has been likened to throwing dogs into the ocean in an effort to save a person from drowning. Obviously throwing dogs into the ocean will not save the person. The only result of this insane action will be that the dogs too will drown. What drowning people need are life jackets.

In my on-going criticism of the Three Rs and their adherents in this column, I have pointed out compelling scientific evidence of where the refinement, reduction and replacement of animals in research are a flawed methodology. While the intent of using fewer animals, or causing less stress and suffering, and/or replacing animals from an experiment has merit from an animal welfare perspective, they are not a valid alternative when the methodology they are supposed to replace does not work. As I have described many times in my writings on NAVS’ website (see Animals in Scientific Research), there are ways animals are used in science that work from a scientific perspective (there may be justifiable ethical reasons to object to these areas) and in those areas, the Three Rs and the development of alternatives make sense. However, for research intended to predict the safety or the effect of a substance in humans by testing it on another species or to model a human disease in an animal model, by definition there cannot be an alternative to a failed methodology.

An article in the July 9, 2009 issue of Nature entitled, Toxicology for the twenty-first century by Thomas Hartung illustrates the seductive power of the Three Rs and the challenges for organizations like NAVS and other anti-vivisectionists. [Thomas Hartung is director of the Johns Hopkins Center for Alternatives to Animal Testing (CAAT). He is in the Department of Environmental Health Sciences at the Johns Hopkins University Bloomberg School of Public Health, and is Doerenkamp-Zbinden Professor and Chair for Evidence-based Toxicology. In addition, he sits on numerous committees and has received awards from animal protection organizations recognizing his many contributions to animal protection.]

This article points out the purpose and complexity of regulatory toxicology in ensuring health and safety. We agree with Hartung’s many criticisms of the current system’s reliance on animal models when he asks what is wrong with the current approach to toxicology testing:

There is almost no other scientific field in which the core experimental protocols have remained nearly unchanged for more than 40 years . . . The first issue is the extent to which animal models reflect human responses. It is clear that the use of animals has limitations: we are not 70 kg rats; we take up substances differently; we metabolize them differently; we live longer (allowing certain diseases to develop and prompting evolutionary adaptations to protect against them); and we are exposed to a multitude of environmental factors.

After asking the crucial question of how useful are animal models, Hartung presents several examples that clearly show the limitations of preclinical animal studies and prove that other species cannot predict the outcome in another species:

In one study regarding pharmaceuticals, 43% of toxic effects in humans were correctly predicted by tests in rodents, and 63% by tests when non-rodent animals were also included. (Emphasis added.)

Another example pointed out that one out of five drug candidates fail as a result of toxicity only after clinical trials.

This essay also points out the scope and costs associated with animal experimentation: Hartung estimates that $14 billion is spent annually on animal experimentation internationally (about $2 billion on toxicological studies) and that more than 100 million animals are sacrificed!

But after presenting a compelling case for the failure (in his words, “the limitations”) of animal models, Hartung’s solution of “designing integrated testing strategies” includes continued reliance on the traditional, nonscientific, vivisection position of more animal studies.

This is the challenge for those of us concerned with both ending the use of animals in science and who have a deep respect for science. Those efforts that promise to reduce, refine and replace the use of animals by continuing to rely on their use mislead and continue to legitimize a methodology that does not work at solving today’s complex problems. Hartung’s solution does not offer any reason to suspect animal tests can be used to keep bad drugs off the market, clear good drugs, or predict a drug’s actions. See the AFMA article in Philosophy, Ethics, and Humanities in Medicine for more on this.

The answer to the question, what should toxicology do for the twenty-first century, is both easy and difficult. The easy part is “stop using animals because animal testing does not predict human response.” The modality simply does not work. The difficult aspect of the question is that nothing else does either. Scientists need to develop predictive technologies that can be implemented in preclinical testing. But the lack of those predictive technologies does not justify the continued use of a failed one.

Using animals in toxicity testing has been likened to throwing dogs into the ocean in an effort to save a person from drowning. Obviously throwing dogs into the ocean will not save the person. The only result of this insane action will be that the dogs too will drown. What drowning people need are life jackets.

We don’t have them and we need them.

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