Zebrafish are not protected by legislation in many countries until they reach the first feed stage, typically at five days post-fertilisation. If they exhibit similar responses to adults when responding to pain and other stimuli should they be given more protection?
Refinement refers to the use of methods that help to minimise animal suffering in the laboratory. Research in this area has increased significantly over the past two decades. However, the extent to which refinements are applied in practice is uncertain. To provide an indication of the implementation and awareness of refinements, we reviewed the experimental techniques for 684 surgical interventions described in 506 animal research applications sent to the German competent authorities for approval in 2010. In this paper, we describe and discuss the appropriateness of the proposed humane endpoints and killing methods. We found that, when the investigators included humane endpoints in their application, these were often lacking in detail and/or were to be implemented at a late stage of suffering. In addition, the choice of method to kill the animals could be improved in the majority of the applications. We provide recommendations for future improvements, based on the recent literature. To ensure scientific rigour, avoid needless animal suffering and enable an accurate harm–benefit analysis, animal researchers have to be knowledgeable about refinement methods and apply them effectively. To assess compliance and ensure that only those studies in which potential benefits outweigh the harms are carried out, reviews such as ours — as well as retrospective assessments of actual harms and benefits — should be conducted widely and regularly, and the findings should be published.
Phase 0 approaches, including microdosing, involve the use of sub-therapeutic exposures to the tested drugs, thus enabling safer, more-relevant, quicker and cheaper first-in-human (FIH) testing. These approaches also have considerable potential to limit the use of animals in human drug development. Recent years have witnessed progress in applications, methodology, operations, and drug development culture. Advances in applications saw an expansion in therapeutic areas, developmental scenarios and scientific objectives, in, for example, protein drug development and paediatric drug development. In the operational area, the increased sensitivity of Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS), expansion of the utility of Positron Emission Tomography (PET) imaging, and the introduction of Cavity Ring-Down Spectroscopy (CRDS), have led to the increased accessibility and utility of Phase 0 approaches, while reducing costs and exposure to radioactivity. PET has extended the application of microdosing, from its use as a predominant tool to record pharmacokinetics, to a method for recording target expression and target engagement, as well as cellular and tissue responses. Advances in methodology include adaptive Phase 0/Phase 1 designs, cassette and cocktail microdosing, and Intra-Target Microdosing (ITM), as well as novel modelling opportunities and simulations. Importantly, these methodologies increase the predictive power of extrapolation from microdose to therapeutic level exposures. However, possibly the most challenging domain in which progress has been made, is the culture of drug development. One of the main potential values of Phase 0 approaches is the opportunity to terminate development early, thus not only applying the principle of ‘kill-early-kill-cheap’ to enhance the efficiency of drug development, but also obviating the need for the full package of animal testing required for therapeutic level Phase 1 studies. Finally, we list developmental scenarios that utilised Phase 0 approaches in novel drug development.
It has now been 11 years since the EU’s new chemicals legislation (Regulation No. 1907/2006 concerning the Registration, Evaluation, Authorisation and Restriction of Chemicals [REACH]) came into force. Two important statements in the REACH Regulation in relation to animal testing and alternatives are: Article 1(1), which states that one of its purposes is to promote alternative methods; and Article 25(1), which states that animal testing should be used as a last resort. This review looks at the mechanisms that were put in place within REACH to achieve these aims and asks, not only if they are being implemented properly, but also if they have been sufficient. Whilst the chemical industry has heavily used data-sharing and read-across, this review concludes that nevertheless over 2.2 million animals have already been used in new tests for REACH registrations. This equates to an annual average of 275,000 animals; 58,000 more per year than the best-case estimate made by the European Commission in 2004. The use of in vitro and (Q)SAR approaches as standalone replacements for animal tests has been relatively low. The levels of funding for research into alternative methods remain low, and there are concerns over the speed of formal adoption of those that have been validated. In addition, there have been issues with the recognition that testing as a last resort and the promotion of alternative methods applies to all parties, including the Commission, Member States and the agency responsible, the European Chemicals Agency. This review provides ten recommendations for better implementation of these two key aspirations, as well as lessons to be learned for future similar legislation.