Many scientifically reliable research methods exist which are superior to using animals to learn about human disease or predict the safety of new drugs.
Microdosing – a new method of obtaining human metabolism data, which enables potential new drugs to be tested safely in humans at an earlier stage. Microdosing relies on the ultrasensitivity of accelerator mass spectrometry (AMS), one of the most sensitive measuring devices ever invented. AMS is so sensitive that it could detect a litre of liquid diluted in all the oceans of the world! Currently, 40% of drugs fail in Phase I clinical trials, which take up to 18 months and cost £3-5 million. Microdosing could screen out drugs destined to fail earlier, faster and cheaper; microdosing takes only 4-6 months and costs £0.25 million per drug. Its accuracy at predicting human metabolism is unsurpassed. EU and US regulators have endorsed the use of microdosing to improve the speed and safety of drug development. See www.xceleron.co.uk, www.vitaleascience.com
DNA chips – enable the study of pharmacogenetics, which, in turn, enables the practice of personalised medicine. This is the concept that since each person is genetically unique, medicines should be designed for individuals, rather than our current ‘one-drug-fits-all’ approach. DNA chips are glass slides the size of a postage stamp, studded with an array of genes or fragments of DNA. A sample of DNA tagged with fluorescent dyes is exposed to a new drug, and then washed over the chip. When the genes on the chip match the DNA in the sample, they stick together and the colours reveal which genes have been activated or suppressed by the experimental drug. See, for example, www.simugen.co.uk
Microfluidics chips – again just 2cm wide, have etched into them a series of tiny chambers, each containing a sample of tissue from different parts of the body. The compartments are linked by microchannels through which a blood substitute flows. The test drug is added to the blood substitute and circulates around the device; thus mimicking what goes on in the body on a micro scale. Sensors in the chip feed back information for computer analysis. Hurel (Human relevant) are pioneering this field. See www.hurelcorp.com
Human tissue – all that we know about HIV/AIDS has come from studying humans and human tissue, particularly blood. Similarly, everything we know about Alzheimer’s and Parkinson’s diseases has been learned by studying patients and their tissues. According toDr John Xuereb, Director of the Cambridge Brain Bank and Wolfson Brain Imaging Centre: ‘Alzheimer's, Parkinson's and other neurodegenerative diseases occur in humans and it is in human tissue that we will find the answers to these diseases.’ New drugs can be tested in human tissues, ethically obtained with fully informed consent, before they are given to volunteers in microdose studies. Companies such as Asterand work exclusively with human tissue because it is more appropriate than animal tissue. See www.asterand.com, www.biopta.com
Computer modelling – virtual human organs and virtual metabolism programmes can now predict drug effects in humans more accurately than animals can. Computers can be used to design the molecular structure of drugs to target specific receptors. For example, the protease inhibitors for patients with HIV were designed by computer and tested in human tissue cultures and computer models, bypassing animal tests due to the urgent need for a treatment. In 1997, Roche Pharmaceuticals had a new heart drug approved on the strength of data from a virtual heart because the animal data was inconclusive. Research teams around the world are working on a 'virtual human', which is designed to predict drug metabolism and metabolite interaction with any given organ – information that animal models will never be able to provide. Scientists can simulate experiments in silico (on computer) in minutes that could take months or years to do in the lab or clinic. See www.entelos.com, www.physiome.org
Autopsies – though neglected of late for a number of reasons, post mortem studies remain the best method of studying the effects of a disease on the whole body and correcting frequent misdiagnoses. Their value cannot be overstated.
Epidemiology – studies lifestyle factors in populations to find correlations that might be significant. Epidemiology linked smoking to cancer; high cholesterol to heart disease; and folic acid deficiency in pregnancy to spina bifida. Large new projects promise to find many more such associations. See www.ukbiobank.ac.uk
Stem cell research – offers potential promise of treatment for a wide variety of diseases. Human stem cells have already been used successfully to treat some leukaemias, as well as improving outcomes for heart attack patients and for some patients suffering from Parkinson’s disease. Donated adult stem cells and umbilical cord stem cells can be engineered to provide an ethical source of human stem cells for research.
New imaging technologies – such as magnetoencephalography (MEG), magnetic resonance imaging (MRI), functional MRI (fMRI), magnetic resonance spectroscopy (MRS), positron emission tomography (PET), single-photon emission computed tomography (SPECT), event-related optical signals (EROS) and transcranial magnetic stimulation (TMS) are offering a view of the human body –in particular, the brain – that cannot be gained by studying animals.
Post-marketing drug surveillance – could help to identify unexpected side effects of new drugs much sooner; thus reducing the burden of adverse drug reactions – currently the 4th leading cause of death in the western world.
Clinical research – has been and will remain the bedrock of medical practice. But many medical treatments have never been studied for efficacy. Large clinical studies are needed to establish whether current practice is actually the best, evidence-based option. Some long-established practices have – shockingly – been shown to be more harmful than helpful, eg. hormone replacement therapy for preventing heart disease and corticosteroids for reducing brain injury.
Prevention – is always more effective than cure. It is estimated that 80% of all cancers and heart disease – our two biggest killers – could be prevented. Funding further research into establishing preventive factors would be money well spent.Testing drugs and chemicals on animals does not offer even a 50% likelihood of predicting their effects in humans. Likewise, researching human disease using animals is often misleading and can result in human harm, including death. Replacing the animal model is not about finding a one-to-one replacement for every current use of animals: that would be futile since the way animals are currently used is ineffective. We need to use research techniques that are genuinely effective; such as those described above. Only by devoting our resources to human-specific research can we be confident that we are doing our utmost to ease human suffering from disease.