Our 3Rs commitment

Our safety assessment team has co-developed, validated and championed the use of an external telemetry (radio-transmitter) method to assess the effects of potential new medicines on electrocardiogram (ECG – a study of heart function) in dogs. The new method reduces the adverse effects caused to the dogs, enhances the value of the scientific data obtained, and helps to avoid the use of around 120 dogs annually across AstraZeneca.

External telemetry involves placing recording pads on the animal's chest, with the recording leads attached to an external radio-transmitter, all held in place by a specially designed jacket. The dogs are able to move freely around their pens whilst the ECG is continuously recorded. The external method is replacing more conventional studies, in which the dogs are restrained in harnesses for 30-second 'snap-shot' recordings of ECG.

Because it avoids restraint, the new method is an important refinement that greatly reduces the stress caused to the dogs. Moreover, by enabling continuous recording, the method enhances the value of ECG data that can be collected early in the drug development process – for example, determination of the time course, magnitude and reversibility of any changes in ECG and better detection of low incidence effects. This has enabled earlier identification and discontinuation of compounds likely to affect heart function, thereby avoiding further animal studies; and has eliminated the need for stand-alone safety pharmacology studies to assess chronic effects of potential medicines on ECG involving animals with surgically implanted telemetry devices. As a result, it is estimated that the new approach has helped to avoid the use of around 120 dogs a year across AstraZeneca.

The team's work has also lead to acceptance of external telemetry as the preferred approach for similar studies involving non-human primates, where it looks set to deliver even greater scientific and animal welfare benefits.
 

Our scientists brought a new monoclonal antibody medicine to clinical trials on the basis of in vitro data and information from extensive testing involving genetically altered mice, avoiding the use of non-human primates. The data satisfied regulatory authorities in the US, Canada and EU that the compound is sufficiently safe and effective to be tested on patients.

This provides important 'proof of principle' that approval for clinical trials of mAbs may be possible without including data from studies in non-human primates. It is hoped that the new mAb will become an important treatment for potentially life-threatening cancers, such as lymphoma and leukaemia, and certain auto-immune diseases.

Note: Monoclonal antibody (mAb) medicines are highly specific to their intended molecular targets in the human body. Similar targets are often found only in other primates and so non-human primates are usually the preferred species for pre-clinical testing of new mAbs. However, in this case our team took an alternative approach, using mice that had been genetically altered by inserting a human gene that enabled them to express the exact human targets for the new mAb. Mice from the genetically altered colony will remain available for future studies, and have already been used to help in the development of another similar molecule.

Our scientists have pioneered, developed, and validated the use of a combined telemetry and automated blood sampling system in rats. This allows effects of potential new medicines to be measured on a wide range of bodily functions simultaneous with blood sampling and urine collection. This enables information on changing levels of a compound in the bloodstream to be matched with its effects on bodily functions (e.g. heart-rate, blood pressure, body temperature, EEG and renal function) in the same animal. In the past, these sets of data have had to be recorded separately, in different groups of rats, requiring more animals. By recording these aspects simultaneously from the same animal, the new system has enabled a significant reduction in the number of rats used to select the most promising compounds for further development. Most importantly the data (based on levels of stress hormones) indicated the integrated system was no more stressful to the animals than previous methods.

Our Lund site has greatly reduced the number of rats and mice needed to provide white blood cells for in vitro (test-tube) studies used to detect the anti-inflammatory potential of compounds at an early stage in medicines development. Human cells are used in these studies as far as possible; but rodent cells are also needed to check that the compounds are active in the animal species that will be used for later, more extensive testing. This early in vitro testing substantially reduces the number of animal studies needed later in the project. By switching the source of white cells from circulating blood to spleen we have been able to reduce our use of rats and mice for this purpose by more than 90%.

Our scientists have reduced and refined the use of non-human primates to test the safety of monoclonal antibody therapies during pregnancy. Through careful and critical evaluation of conventional testing methods, they have developed a new study design that reduces the number of non-human primates by more than 50% (down from over 100 to around 40 for each new therapy. The team has won the international regulatory authority’s confidence in their new design, which is now cited as the preferred approach, on both scientific and animal welfare grounds. Importantly, the team has successfully lobbied for the tests to be done at a much later stage in the drug development process and so further reducing the use of non-human primates.Monoclonal antibodies are highly specific to human physiology, so non-human primates are in most cases the only relevant animal model to use because of their similarity to humans. However the decision to use this animal species is always made on a case by case basis taking into account all possible alternatives.

• The 3Rs award went to a team of scientists who validated a complex computer-controlled mechanical and chemical model of the upper part of the human digestive system (stomach and small intestine) for use in formulation development (the process of deciding how best to combine new medicines with other ingredients to ensure they can get to where they are needed in the body at the appropriate concentration). At AstraZeneca in the UK, pioneering use of this simulation has virtually eliminated the small number of dogs needed to develop formulations of medicines for cancer, inflammation, infection and cardiovascular disease.
• AstraZeneca scientists in Boston have made a number of refinements to pharmacokinetic (PK) studies involving rats. These have enhanced animal welfare, reduced the number of animals used, and improved the scientific value of the data obtained. The refinements include changes to blood sampling procedures, and development and validation of a novel method of sequential dosing. Overall, these changes have led to a 50% reduction in the use of rats in PK studies at this site.
• A specific study in rodents used to test side effects for new medicines on the digestive system (e.g. constipation and diarrhoea) have undergone considerable refinement at AstraZeneca. Typically, animals have their food withdrawn overnight (around 18 hours) prior to testing, so as to reduce variation in results. However, our scientists have shown that, although a period of fasting is still needed, reducing the time to 6 hours greatly improves animal welfare without compromising scientific validity. A 6-hour fasting time is now used in the UK, during the daylight phase when food intake by rodents is minimal, benefiting many animals. AstraZeneca scientists using other tests that require fasting are also evaluating this refinement.
• Our respiratory and inflammation research area (RIRA) has reduced the use of animals in tests needed to support products that combine two therapeutic agents in an effort to bring potentially improved treatments to patients. They have shown that tests on live guinea pigs are not needed for this purpose; and that, instead, in vitro (test-tube) studies using guinea pig tissue can successfully demonstrate the additional benefit of combining two compounds. With the need for future combinations to be evaluated, use of these more clinically relevant alternatives will significantly reduce the number of guinea pigs needed in RIRA - with tissue from just four guinea pigs needed per combination instead of up to 160 live animals.)
• AstraZeneca scientists have refined and reduced the use of rats in studies carried out to identify compounds that might be used to treat obesity and associated type-2 diabetes. The new method requires 40% fewer animalsand yields results directly applicable to humans more quickly. This work was presented at ’The 3Rs Today’, an event hosted by the UK National Centre for Replacement, Refinement and Reduction of Animals in Research, where it won the reduction prize. Find out more about the National Centre for 3RS.
• Our biologics team is working with world class academic institutions to share tissue samples and limit the need for additional animals at both organisations. In addition, one of our staff worked with a cage manufacturer to design a balcony system in mouse cages to provide additional space and movement areas.

• Our 2008 global award for best practice in 3Rs was made to the scientist who led a European collaborative project, involving 18 pharmaceutical companies and contract research organisations, which demonstrated the limited value of specific single dose acute toxicity studies in pharmaceutical development. The studies were a regulatory required test ahead of first administration of a new medicine to humans. The project demonstrated that this is not necessary, because the information required to assure human safety can be obtained from other, more refined animal studies. As a result of this work, AstraZeneca has not conducted such studies since 2006 and other companies are also taking up this approach, which has led to a collective 70% reduction in the use of rats and mice for these studies across Europe (approximately 15,000 animals each year). The output of the work is now leading to revision of international regulatory guidelines so that these animal tests will no longer be required. Following the success of this project, a similar approach is now being used to examine the need for acute toxicity tests in other sectors (e.g. veterinary medicines and chemicals used in agriculture). AstraZeneca is again taking the lead, co-ordinating an acute toxicity team under the umbrella of the European Partnership on Alternative Approaches (EPAA).
• In the US a project is underway to ensure that, wherever possible, tumour tissues from mice used in cancer studies are not discarded, but are collected and stored for further use. The resulting enhanced tissue bank provides our scientists with linked protein, RNA and tissue from a wide range of tumour types, enabling them to make early, rapid, and comprehensive assessments of potential new treatments for cancer, without the need to generate additional tumours in mice. In 2008, samples of 200 different types of tumour were submitted to the bank and 24 different AstraZeneca projects were supported in the US, UK and China, directly sparing up to an estimated 7500 mice that would otherwise have had to be used to generate the tumours. A database linked to the tumour tissue bank also went live in 2008, further increasing its scientific value. In the future, these benefits are set to increase as more tumour samples are added to the bank and the database of scientific information gained from using them grows.

• In 2007, we completed our investment of over £40 million in facilities for housing and care of dogs in the UK and Sweden. These investments are in line with the most recent scientific consensus on how best to refine dog husbandry in a laboratory setting. They will provide state-of-the-art kennels, stimulating environments and outdoor playgrounds in which the dogs will be able to socialise with each other and with the staff who care for them.
• We increasingly use non-invasive imaging techniques such as ultrasound and MRI (which are also used for human diagnosis) to study the effects of new medicines on the progress of disease in living animals. Our scientists have been instrumental in developing an innovative ultrasound method that enables them to “look inside” a mouse’s arteries and follow the effects of potential medicines on the development of atherosclerosis in “real time”, in the same animal, over its whole life. This method helps to improve the scientific accuracy of the studies, and reduces the number of animals needed to obtain the required data.
• Databases that capture information on the properties of existing medicines and other similar compounds can help scientists to predict, at an early stage, how new compounds are likely to behave in the human body. This enables earlier, more informed choices about which compounds to take forward for further development – which in turn helps to avoid any unnecessary animal testing on compounds likely to fail. We use a range of such databases, and in 2007 increased predictive power by rolling out across all sites the most comprehensive pharmacological profiling database currently available – Bioprint®, licensed from Cerep.

• We use in vitro hepatocytes (liver cell) tests to assess how a compound is eliminated from the body, allowing us to discard unsuitable compounds without the need for animal studies. We have also developed an automated test for rat hepatocytes, the accuracy of which is proving less variable than the previous manual assay. These efficiencies mean that at this stage of research, we can test more compounds and make compound selections without the need for animal studies.
• Our use of synthetic animal protein in drug development means that some techniques which required the use of animal tissue have been replaced, and the predictability of the animal studies that we must still do has been improved, leading to the use of fewer animals overall.

• We use leading-edge computer technologies to predict more accurately how a potential medicine may act in the human body (for example, how it will be absorbed and distributed). This enables elimination of unsuitable compounds early in the discovery process and stops their progression into animal studies.
• New medicines for arthritis aim to relieve pain and improve mobility. We use a new system of imaging and analysing how an animal with arthritis walks so that we can immediately detect any subtle changes in mobility following treatment. This is a major welfare improvement as the study is less stressful for the animal and can provide more accurate data using a smaller number of animals.
• A European project, initiated by AstraZeneca, could more than halve the 1.6 million fish used in environmental safety tests in Europe. Subject to regulatory approval, initial testing of chemicals will be undertaken with algae and water fleas (daphnia) to predict the threshold of toxic concentration. This will then limit the number of concentrations that need to be tested in fish, and so reduce the numbers used.