The limitations of preclinical animal models have encouraged the development of more human-based in vitro and in silico methods that offer the potential of being more predictive, reliable and accurate approaches to identifying safety issues with drugs and other chemicals. Despite their advantages, however, these non-animal testing methods have not seen widespread acceptance.
What barriers are standing in the way? And what can be done to overcome these barriers? A recent article in Alternatives to Laboratory Animals addressed these important questions.
The challenge of transitioning from established animal-based methods with historical data to new approaches is certainly a contributing factor. Some scientific barriers must also be addressed, including the recognition that alternatives will not realistically replace traditional animal tests on a “like-for-like” basis. However, if one considers that data from alternatives can be combined together in meaningful ways, it is quite possible that these approaches could replace animal tests.
Another obstacle is formal validation of alternatives to assess their reliability and relevance. Validation studies are rigorous, expensive and time-consuming, and some worry that the validation process actually prevents the introduction of alternatives, rather than promotes them. Interestingly, animal-based tests currently in use have not undergone formal validation themselves.
Regulatory acceptance of alternatives is another challenge. Confusion over regulatory guidelines can lead researchers and regulatory bodies to believe that animal data is required when it isn’t. Also, researchers may be advised by regulatory consultants to use traditional, less “risky” animal methods, in part, because regulators are more comfortable interpreting data from animal studies for which they have more experience. Additionally, regulatory acceptance of a non-animal alternative by one regulatory agency does not guarantee acceptance by others, indicating a great need to improve the global harmonization of data requirements.
What must be done to overcome these hurdles? The ATLA article summarized the steps well: “In order to realise the potential of a human-based approach, we must continue to research and refine human-based tests, improve and accelerate validation, educate researchers, regulators and insurers about the limitations of extrapolating between species and the advantages of a human-focused approach, clarify, proactively communicate and enforce official guidelines, and most importantly, set timelines for action.” Failure to do so will continue to postpone the critical shift from animal models to more human-relevant approaches indefinitely.
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-Dr. Pam Osenkowski, Director of Science Programs
Barriers to the Uptake of Human-based Test Methods, and How to Overcome Them
Although there is growing concern as to the questionable value of animal-based methods for determining the safety and efficacy of new medicines, which has in turn led to many groups developing innovating human-based methods, there are many barriers to their adoption for regulatory submissions.
For more information see: ATLA