Non-human primates are used in medical research because of their similarities to human beings. Results from research on non-human primates can often be applied to humans, and scientists have learned much about diseases, disorders, prevention and treatments for both humans and animals. Using animals that are so similar to humans, however, raises serious ethical concerns, which is why the use of non-human primates is monitored and strictly regulated. Animal testing for cosmetics was entirely banned in the European Union in March of 2013, and much also has been done to specifically safeguard non-human primates: non-human primates used for research, for example, can no longer be obtained from the wild unless the objectives of the study specifically requires the use of wild-caught; and the use of great apes has been prohibited. As long as non-human primates continue to be used for medical research, the European Commission strongly advocates the "3Rs principle", now a legal obligation embedded in the EU legislation to: Replace non-human primates with viable alternatives whenever feasible, Reduce the use of non-human primates and Refine scientific procedures and the care and treatment of the animals. This Opinion is an update of the 2009 Opinion and addresses issues specifically related to implementing the "3Rs principle".
Navigation
- 1. Introduction
- 2. Background
- 3. Current use of non-human primates
- 4. Alternatives to the use of non-human primates
- 5. Reducing and refining the use of non-human primates
- 6. Determining a timeline for phasing out the use of non-human primates
- 7. Implications of an EU-ban on the use of non-human primates
- 8. Research areas to explore to further the 3R principle
- 9. Conclusion and Recommendations
3. CURRENT USE OF NON-HUMAN PRIMATES
3.1. In which areas of research are non-human primates still used today?
Non-human primates are mainly used in the development and safety testing of pharmaceuticals and medical devices and in research related to the treatment and prevention of infectious diseases and neuroscience. To a far lesser extent they are used in research related to ophthalmology and (xeno)transplantation.
3.2. Why are non-human primates needed in the development and safety testing of pharmaceuticals and medical devices?
Before a new pharmaceutical can be introduced on the market, it has to be tested on humans during clinical trials. The purpose of animal testing is to safeguard the health of the people taking part in these trials. The vast majority of drugs initially selected for development are rejected during this process, either because they are not effective or because they cause unwanted side-effects.
Newly designed drugs go through a series of preliminary laboratory tests that do not involve animals. Based on the results, the best ‘candidate’ drugs are then tested on animals to see if they work, and to identify any possible health risks. Drugs are often tested on rodents but the results are difficult to extrapolate to humans because of some fundamental differences between the two species. Therefore, pharmaceuticals must also be tested on a second species other than rodents, often dogs. Normally, there is no routine requirement for the use of non-human primates as a second species. While safety testing of new pharmaceuticals and other medical products represents one of the major uses of these non-human primates, only few candidate pharmaceuticals are actually tested on them.
Non-human primates should only be used when it is scientifically demonstrated that none of the other non-rodent species commonly used in safety testing is appropriate for the purpose of the study.
For instance, because no other animal species is as close to humans in their anatomy or in the way they respond to drugs, non-human primates may be preferred over other mammals to test the safety of the following drugs:
- drugs with possible effects on female genital organs
- drugs with possible effects on the eyes
- drugs that may cause vomiting
- drugs that affect how the blood coagulates
- biopharmaceuticals (especially monoclonal antibodies)
- central nervous system (CNS) pharmaceuticals (drugs with psychoactive properties)
- drugs capable of causing birth defects or that affect fertility
Non-human primates have been used effectively to test the safety of major new treatments for diseases such as severe asthma and certain eye diseases. Studies on non-human primates are more likely to identify possible hazards to humans.
Because humans and non-human primates develop in a similar way in the early years, young non-human primates may also be the preferred option for specific safety testing of drugs aimed at infants and children.
In some cases non-human primates are not the best animal choice, for instance dogs are more suitable for testing toxicity to the liver. It is also important to note that animal testing on non-human primates does not always predict all harmful effects on humans. The cynomolgus monkey, for example, has been found – unlike humans - to be remarkably resistant to liver injury caused by paracetamol, which is an important finding because cynomolgus monkeys are the non-human primates used most commonly to assess drug safety.
Therefore, safety assessments of new products require information from both animal and non-animal testing.