With potential new drugs being tested rocketing each year, the time for a drug to reach the market taking 10-15 years, the cost of drug development increasing and the higher use of animals for animal testing, Frontier asks: is animal testing really viable?
Animal testing is a heated debate which affects the healthcare system and ultimately your health. Any discussions by the media show a definite war between sides with little in-between. Those for animal testing praising the medicine created from it and those against usually claiming moral reasoning.
But what do most people think? In a view survey, 64% of the UK public agrees to animal testing to aid medical research, if no alternative exists. However, the UK survey found only 7% of respondents said they knew anything about the 3Rs. The 3Rs are required by law to be considered and evaluated before any animal test starts and are considered throughout the testing period. Researchers must evaluate refinement, reduction and replacement of animal use before planning an animal experiment.
I will use these basic principles of animal testing to evaluate the evidence for and against animal models and explore possible alternatives.
Refinement: how can I improve my method to maximize animal welfare?
In medicine, the animal model is required by law so it’s no surprise that we owe so many modern medicines to them. This must mean the method is valid than?
Animals, especially chimpanzees, are very biological similar to humans. Chimpanzees share 99% similar genes to us homo sapiens but this one percent difference makes them also different in many ways other than just appearance. For example, chimpanzees do not develop AIDs after HIV infection and are immune to Hepatitis B.
The most famous example of a positive response to a drug from an animal that became harmful to humans is thalidomide. After the drug passed animal testing it was used as a morning sickness deterrent causing 10,000 babies to have birth defects.
Scientists have been trying to improve the scientific method by using more Genetically Modified (GM) animal models. Breeding GM fish/mice now constitutes to more than 50% of animal model procedures. There is just reasoning for this as GM models have given us understanding and new treatments for Alzehiermers, cancer, obesity and diabetes.
The species are altered genetically as an embryo and then experimented on to see how the change in genome affects them. The animals are modified to be more similar to humans than normal mice which reduced costs and breeding required in normal testing. Scientists have therefore discovered a method to refine the welfare of animals used for an experiment. Scientists hoped this will eventually decrease the number of animals in studies. But with the numbers of GM animals on the rise, it doesn’t seem to be so.
GM seems more ethical, however, the method is not perfectly sound yet. There is conflicting evidence from GM studies and euthanasia is common for the transgenic and wild type animals not suitable for use in the experiment.
Reduction – how can I minimise the numbers of animals I use (e.g. appropriate experimental design)?
The literature is lacking in solid evidence that animal models benefit society due to the lack of systematic reviews of current and future research methods. A 2004 review in the British Medical Journal reviewed 277 papers but only 25 were systematic reviews. The authors discovered found lack in blinding and randomization in animal models, which is surprising as this is a necessity in clinical trials. More reviews are needed as the authors found many animal trials in different countries made the same mistake twice.
‘Discordance between animal and human studies may be due to bias or to the failure of animal models to mimic clinical disease adequately.’ The authors stated.
Now is the time to look towards alternatives as drug prices continue to increase due to the ineffective method. For every billion dollars going into R&D, we have less new drugs. Each year, more money is funding clinical drug trials but less is available on the market. How did this happen? Part of the cause behind this trend is our reliance on animal models. More public funding can be directed towards finding alternatives to the current clinical trial method, bringing us onto the third R, Replacement.
Replacement – Would an alternative to animal models be more appropriate?
Described as the ‘weakest link’ in animal models, since replacement would set back biomedical research, but there are currently some exciting movements in the replacements of using animals for drug testing
Organ based assays used at early stages in drug development. An example of this is microdosing which involves extremely low, inactive doses of a new drug used on humans. See the video below:
Another micro technology could potentially replace animal models. Microchips that mimic human organs (e.g. lungs), as described in the video below.
These new methods could aid companies lacking in R&D funding, due to continuing government cuts.
So it is clear further research into the viability of animal models is needed. Research into improving the current method has developed through GM animals for specific diseases and conditions. The animal model isn’t perfect but there are developments in place to improve it, which gives a promising hope for the future.
By Meike Simms - Online Media Intern