Alternative approaches to animal testing

In 1959, The Principles of Humane Experimental Technique was published by Russell and Burch, introducing the 3Rs concept (replacement, reduction, and refinement) regarding animal use in the scientific community. Just over 60 years later, it is timely to review progress to date and the future outlook regarding alternative approaches to animal testing.

The US Environmental Protection Agency (EPA) announced elimination of all mammal study requests and funding by 2035, and the Dutch Minister for Agriculture aims for the Netherlands to become the ‘world leader in innovations without laboratory animals by 2025’. These ambitious objectives by the Netherlands and the US are backed also at an EU level, with both citizens and industry anticipating significant reductions in the coming years.

It is important to acknowledge that to date, most scientific breakthrough and biomedical success is grateful to animal use and testing, without which many achievements would not have been possible (for example, increases in cancer survival rates, vaccinations, and the eradication of diseases such as smallpox). With the modern advances of science and technology today, we are embarking on a new era of methodologies to understand disease and mechanisms in humans.

PierFranco Conte ESMH scientistProfessor Pierfranco Conte, Professor of Oncology at the University of Padova and Director of the Division of Medical Oncology 2 at the Istituto Oncologico Veneto in Padova : “Animal models are still essential for some research fields, e.g. oncology, pharmacology, immunology, and neurology, where complex interactions between cells and tissues are essential components of the research. However, the increasing motivation of scientists to optimise and standardise experimental systems has led to the development of better experimental practices that include preliminary testing in vitro and ex vivo screening techniques before testing in vivo”.

Professor Conte and colleague Professor Vincenzo Ciminale, an experimental oncologist, have noted a steady decline in the last 10-15 years in the number of animals used. They commented that they have observed “even more importantly, a dramatic improvement in the attention to the animals’ well-being and on the appropriateness of the animal care procedures”. They predict “with the development of technologies and 3D ex vivo cultures such as spheroids and organoids, the use of experimental animals will be further reduced in the future”.

European progress

Legislation has been in place in the EU since 1986 covering the use and protection of animals for scientific purposes. With Directive 2010/63 the EU has clearly set out the ultimate goal as full replacement and has explicitly engrained the 3Rs principles in legislation. The Directive also formally established the European Union Reference Laboratory for alternatives to animal testing (EURL ECVAM) at the European Commission’s Joint Research Centre (JRC) with a mandate  to support the development, validation and international acceptance of alternative methods.

Maurice Whelan ESMH scientistProfessor Maurice Whelan, head of EURL ECVAM at the JRC, Ispra, Italy : “The JRC is the Commission’s science and knowledge service and has been active for nearly 30 years promoting the 3Rs in numerous ways both for toxicological testing and more recently for use in basic and applied research. We don’t work alone of course but collaborate closely with regulatory bodies, research consortia, NGOs and government agencies all over the world to ensure we’re all pulling in the same direction”.

In 2005, the European Partnership for Alternative Approaches to Animal Testing (EPAA) was created which is a public-private partnership involving the European Commission and industry sectors with the vision of ‘the replacement, reduction and refinement (3Rs) of animal use for meeting regulatory requirements through better and more predictive science’. Their mission involves promoting the development and acceptance of novel alternative approaches. The focus of their annual conference in October 2019 was on building confidence in the use of the 3Rs, particularly by government regulators and scientists in industry. Examples through which this is being achieved is through training the next generations of safety assessors in non-animal methods, holding working sessions, and continuing communication and open dialogue between industry, academia, NGOs, regulators and other public and private organisations.

Since 2013, animal testing for cosmetics and the sale and marketing of cosmetics tested on animals has been banned in the EU, while there remains a call for global action and a worldwide ban. A Eurobarometer survey conducted within the 28 Member States (27,672 participants) in 2015 reported that 89% agreed that ‘the EU should do more to promote a greater awareness of animal welfare internationally’. In the year 2017, almost 9.4 million animals were used in the EU for scientific and experimental purposes.

Mrs Tilly Metz, Luxembourgish Member for the Greens/EFA group of the European Parliament: “The Animal Welfare Intergroup of the European Parliament also intends to highlight the need to incentivise animal-free research, and discourage investment in animal-based research in relevant missions and projects of Horizon Europe. We will work towards concrete legislative changes and will come up with proposals and suggestions for higher animal-welfare standards and better controls.”

What are alternative approaches to animal testing?

Before a drug can progress to clinical trial testing in humans, it must be proven to be safe and tolerable. Thus, validated, alternative methods must replace traditional animal testing. Examples of potential models include 2D and 3D human cell and tissue models, organoids, and organ-on-a-chip models, and virtual/computational modelling with the help of innovative technologies and artificial intelligence (AI).

Dr Jason Johnson and PhD student Rosaria Bianco at the University of Bristol have been working on a novel human ex vivo method that replaces rodent use for studying aneurysm formation and progression, funded by the National Centre for the Replacement Refinement & Reduction of Animals in Research (NC3Rs) and the British Heart Foundation. Dr Johnson and his lab have successfully shown that this method works just as well as traditional mouse models.

Dr Jason Johnson ESMH scientistDr Jason Johnson, British Heart Foundation Senior Research Fellow, Associate Professor of Cardiovascular Pathology, and leads the Laboratory of Cardiovascular Pathology at Bristol Medical School, University of Bristol : “Collectively, our findings support the use of this model for future aneurysm studies and provides an alternative for ethically challenging animal experiments, reducing the number of mice used in such studies”.

Alternative models may better predict and model human disease than traditional tests on animals e.g. in terms of toxicity, bioavailability and reproducibility.

Professor Whelan comments, “in many cases, traditional animal testing might provide data that cannot be extrapolated from one species to another and thus can result in misleading conclusions regarding, for example, the safety or efficacy of a drug when used in humans. Currently EURL ECVAM is conducting a set of major studies to review non-animal models currently in use for basic and applied research in seven disease areas, including neurodegenerative (e.g., Alzheimer, Parkinson, etc.) and respiratory diseases (e.g., fibrosis cystic, asthma, etc.). These non-animal models are also promoting innovation and competitiveness within the EU, for example by encouraging creation of new biotechnology enterprises and providing new tools for more efficient drug development and ‘safe design’ of chemicals used in the vast range of products available to us”.

Obstacles and outlook

Regulatory acceptance is one of the biggest challenges facing significant uptake of the 3Rs in the field of regulatory testing. The financial costs of the development of alternative methods is also something that cannot be ignored. There is also, perhaps, a general mind-set that needs to be challenged, adapted and refocused. For example in the toxicology sector, traditionally educated scientists may be more comfortable in continuing in the practices that they know. Mrs Metz argues “we need an evolution of mentalities and attitudes: many scientists are still convinced that we need these tests on animals. One would not be wrong to speak of a tradition, and, as we know, it can be very hard to change so-called « traditions »”. Dr Johnson comments that scientific journals also have a role to play in removing barriers, “there needs to be a change in attitudes from reviewers and journals towards studies that are developing and/or deploying novel alternative approaches to animal testing”.

Dr Johnson notes positive progress in the scientific community – “Attitudes are definitely changing, the NC3Rs provide many conferences and meetings highlighting the 3Rs concept alongside exemplars of best practice”. Professor Conte encourages the EU to promote animal-free research and suggests for example, “increasing funding resources to stimulate the development of innovative models of human disease to minimize or possibly entirely replace animal testing of new drugs”.

Continued, constructive dialogue between all key stakeholders including NGOs, regulators, scientists, and industry is essential to positively progress in the direction of ultimately no longer requiring the need for animal testing. Overall, it appears we are moving in the right direction, with hopefully more rapid and positive changes on the horizon.

Useful links :


Related Content

EU-ToxRisk EU project
A Scientist's Opinion : interview with Prof. Maurice Whelan about Animal testing
A Scientist's Opinion : interview with Pierfranco Conte about Animal testing
A Scientist's Opinion : interview with Dr Jason Johnson about Animal testing
  1. This article raises some important points, but it does simplify some of the issues.

    At the European Animal Research Association (EARA) we fully support the development of animal-free tools to predict and model human disease. Where these are proven to be more effective than animal models they are likely to save scientists considerable time and money in their research. However, in many areas of research, such as neuroscience and cancer, animal models continue to be the most likely method to help achieve medical breakthroughs.

    Unfortunately, it is a fact that progress has been slow to develop reliable animal-free methods in many areas of biomedical research. This was reflected in the actions of the Netherlands government when, in 2018, it officially dropped its target to be ‘a world leader in innovation without laboratory animals by 2025’ and brought in the more realistic aim of being ‘a forerunner in the international transition with animal-free innovation’.

    With regard to the comments of Mrs Tilly Metz, while incentives for animal-free research would undoubtedly help improve the speed of progress, this should not come at the expense of investment in existing methods, such as animal models, which continue to assist the European biomedical sector and help it achieve remarkable results in drug innovation and treatments.

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