Ill-informed arguments perpetuate 'misunderstanding and misrepresentation' of animal research

To describe animal testing as 'outdated and fundamentally flawed' is inaccurate and unhelpful, argues Kirk Leech

By Kirk Leech

29 Mar 2014

The Parliament Magazine recently featured a piece by Emily McIvor claiming that animals were poor predictors of human responses to drugs and that nine out of 10 drugs tested on animals fail during human trials, yet this fundamentally misunderstands how animals are used.

Animals are used to test the safety of the drug, not its efficacy.<br><br>Initially I think it is helpful to explain that most animal research has nothing to do with testing drugs for human consumption. In the UK, about half of experiments are the breeding of genetically manipulated mice and fewer than one per cent of research animals are cats and dogs - most are mice, fish, rats and birds.

Animals are used for medical, veterinary and environmental research. The badger TB vaccine needed to use animals, for instance, and most of the 200 or so cats are used in veterinary research.

When new drugs for humans are tested, a large number of pre-clinical non-animal tests are performed, using a range of methods which include computer models, automatic screening, cell cultures, and microbial studies.

This provides the first filter for preventing toxic or ineffective drugs even reaching the stage where animals are used, reducing both the number of animals and the cost of their use.

So the 'nine out of 10' (which is based on outdated data, the actual figure is closer to 94 per cent) drugs that fail in human tests, are those that passed both animal and non-animal preclinical tests.

The purpose of the animal tests is only to assess whether a drug is safe enough to progress into phase one trials. The licence for use of a drug is based on the clinical trials in thousands of people; therefore, where there is an adverse drug reaction in humans, this is not indicative of inaccurate animal modelling.

"Until there can be transparency without this kind of misrepresentation, and open access to reliable information in the public domain, the polarised and ill-informed opposition to animal research will continue"

In fact, in a poll of almost 1000 biomedical scientists conducted by the science journal 'Nature' more than 90 per cent agreed that the use of animals in research is essential.

The reverse inferences of these statistics must also be told. Animal experiments remove 36 per cent of potential drugs from moving to the next stage; in doing so, they serve as a highly effective measure to prevent potentially harmful drugs being administered to humans.

Following this, of all the drugs which pass phase one clinical trials in humans, 86 per cent will fail in later human trials; and yet the parallel conclusion that humans are an inappropriate model for drug development is rarely proffered.

It is a legal requirement that animals cannot be used where an alternative exists. Their use, therefore, points directly to the lack of a suitable alternative. There is also a broader commitment, enshrined in UK law, to uphold the 3Rs: to reduce, replace and refine animals used in research.

Nobody uses an animal if there's an alternative.

Of course, animal research and testing should never cease to be challenged; its use reflects a carefully balanced ethical assessment: that the discomfort or death of one animal is worth the ease of suffering in thousands of other animals, and humans.

It is not an easy or comfortable conclusion, and continual reassessment should be encouraged. Not only in the interests of ethics, but also of scientific accuracy. Researchers are in no way bound by a misplaced loyalty to tradition.

An article which fails to acknowledge the nuances in this important debate only serves to perpetuate misunderstanding.

Until there can be transparency without this kind of misrepresentation, and open access to reliable information in the public domain, the polarised and ill-informed opposition to animal research will continue.