Social housing of non-rodents during cardiovascular recordings in safety pharmacology and toxicology studies

Dog leukocyte antigen genotyping across class I and class II genes in beagle dogs as laboratory animals

Dog leukocyte antigen (DLA) polymorphisms have been found to be associated with inter-individual variations in the risk, susceptibility, and severity of immune-related phenomena. While DLA class II genes have been extensively studied, less research has been performed on the polymorphisms of DLA class I genes, especially in beagle dogs commonly used as laboratory animals for safety evaluations in drug development. We genotyped four DLA class I genes and four DLA class II genes by locus-specific Sanger sequencing using 93 laboratory beagle dogs derived from two different strains: TOYO and Marshall. The results showed that, for DLA class I genes, 11, 4, 1, and 2 alleles, including a novel allele, were detected in DLA-88, DLA-12/88L, DLA-64, and DLA-79, while, for DLA class II genes, 1, 10, 6, and 7 alleles were detected in DLA-DRA, DLA-DRB1, DLA-DQA1, and DLA-DQB1, respectively. It was estimated that there were 14 DLA haplotypes, six of which had a frequency of ≥ 5%. Furthermore, when comparing the DLA diversity between TOYO and Marshall strains, the most common alleles and haplotypes differed between them. This is the first study to genotype all DLA loci and determine DLA haplotypes including all DLA class I and class II genes in dogs. Integrating information on the DLA diversity of laboratory beagle dogs should reinforce their benefit as an animal model for understanding various diseases associated with a specific DLA type.

Method of measuring effects of study procedures in single and pair housed New Zealand White rabbits (Oryctolagus cuniculus)

Social housing of laboratory rabbits is encouraged and thought to improve animal welfare due to the social nature of this species. However, there is limited published information comparing the physiologic and cardiovascular (CV) effects of paired and single housed adult female rabbits in commonly used laboratory caging. This study describes measurement of heart rate, systolic blood pressure, activity level, body temperature and pairing methods in four female New Zealand White rabbits that were previously implanted with M10 cardiovascular telemetry devices. Data was collected in single housed rabbits having no history of social housing while they were undisturbed in the home cage, during restraint, intramuscular injections and intravenous blood collection. The same animals were then placed in compatible pairs and housed in conventional Allentown caging. As expected, we found increased activity in paired rabbits but no significant differences in body temperatures, and CV parameters in single and paired rabbits undergoing the same procedures. These data suggest that paired rabbits can be used for safety pharmacology studies with minimal impact to data, while supporting improved animal welfare.

Telemetric data collection should be standard in modern experimental cardiovascular research

Cardiovascular (CV) health is often expressed by changes in heart rate and blood pressure, the physiological record of which may be affected by moving, anaesthesia, handling, time of day and many other factors in rodents. Telemetry measurement minimises these modulations and enables more accurate physiological recording of heart rate and blood pressure than non-invasive methods. Measurement of arterial blood pressure by telemetry requires implanting a catheter tip into the artery. Telemetry enables us to sample physiological parameters with a high frequency continuously for several months. By measuring the pressure in the artery using telemetry, we can visualize pressure changes over a heart cycle as the pressure wave. From the pressure wave, we can subtract systolic, diastolic, mean and pulse pressure. From the beat-to-beat interval (pressure wave) and the RR' interval (electrocardiogram), we can derive the heart rate. From beat-to-beat variability, we can evaluate the autonomic nervous system's activity and spontaneous baroreflex sensitivity and their impact on CV activity. On a long-term scale, circadian variability of CV parameters is evident. Circadian variability is the result of the circadian system's activity, which synchronises and organises many activities in the body, such as autonomic and reflex modulation of the CV system and its response to load over the day. In the presented review, we aimed to discuss telemetry devices, their types, implantation, set-up, limitations, short-term and long-term variability of heart rate and blood pressure in CV research. Data collection by telemetry should be, despite some limitations, standard in modern experimental CV research.

Refining Procedures within Regulatory Toxicology Studies: Improving Animal Welfare and Data

Simple Summary

Before any new medicine can be administered to humans, or new chemical marketed, some tests using animals such as fish, mice, rats, rabbits, dogs, or monkeys are performed in order to satisfy the legal requirements of international regulatory and government agencies. These assess the potential for harmful side effects in humans or species found in the environment and to explore how the compound is processed within the body. The housing conditions and procedures performed (such as dosing of compounds and removal of small blood samples) are designed to minimize any pain, suffering, distress, or lasting harm that may be experienced by the animals. These refinements improve animal welfare but can also improve the data quality. Examples of new processes, technologies, or equipment that have been introduced within some UK facilities are shared in this article and provide opportunities to benefit many more animals undergoing testing across the world in the future.

Abstract

During the development of potential new medicines or agrochemicals, an assessment of the safety profile to humans and environmental species is conducted using a range of different in silico and in vitro techniques in conjunction with metabolism and toxicity studies using animals. The required studies are outlined within international regulatory guidelines which acknowledge and support the application of the 3Rs to reduce the number of animals used or to refine the procedures performed when these studies are deemed to be necessary. The continued development of new technologies and adoption of best-practice approaches to laboratory animal housing and study procedures has generated a series of refinements that can be incorporated into animal studies throughout the package. These refinements benefit the welfare of fish, mice, rats, rabbits, dogs, minipigs, and non-human primates (NHPs) whilst maintaining or improving data quality within general toxicology, metabolism, and other studies and can also bring efficiencies to processes that benefit study costs and timings. Examples are shared which cover the following topics: social housing of dogs and NHPs, surgical refinements in the rat bile duct cannulation model for collection of data for metabolism studies, whether fasting is really required prior to clinical pathology sampling, and the use of microsampling for toxicokinetics.

Current Trends of Practices in Nonclinical Toxicology: An Industry Survey

The growth in drug development over the past years reflects significant advancements in basic sciences and a greater understanding of molecular pathways of disease. Benchmarking industry practices has been important to enable a critical reflection on the path to evolve pharmaceutical testing, and the outcome of past industry surveys has had some impact on best practices in testing. A survey was provided to members of SPS, ACT, and STP. The survey consisted of 37 questions and was provided to 2550 participants with a response rate of 24%. Most respondents (∼75%) came from the US and Europe. The survey encompassed multiple topics encountered in nonclinical testing of pharmaceuticals. The most frequent target indications were oncology (69%), inflammation (55%), neurology/psychiatry/pain (46%), cardiovascular (44%), and metabolic diseases (39%). The most frequent drug-induced toxicology issues confronted were hepatic, hematopoietic, and gastrointestinal. Toxicological effects that impacted the no observed adverse effect level (NOAEL) were most frequently based on histopathology findings. The survey comprised topics encountered in the use of biomarkers in nonclinical safety assessment, most commonly those used to assess inflammation, cardiac/vascular, renal, and hepatic toxicity as well as common practices related to the assessment of endocrine effects, carcinogenicity, genotoxicity, juvenile and male-mediated developmental and female reproductive toxicity. The survey explored the impact of regulatory meetings on program design, application of the 3 Rs, and reasons for program delays. Overall, the survey results provide a broad perspective of current practices based on the experience of the scientific community engaged in nonclinical safety assessment.

Supportive care for animals on toxicology studies: An industrial best practices survey conducted by the IQ 3Rs TPS CRO Outreach Working Group

Contract Research Organizations (CROs) conducting toxicology studies on behalf of biopharmaceutical sponsors and others routinely provide supportive care for animals to minimize pain and distress on studies. A large number of guidance documents govern the care of experimental animals, however there is currently no uniform approach on the communication between sponsor and their CRO partners in providing a standard definition of and strategies for administering supportive care in toxicity studies. This survey was conducted by the CRO Outreach Working Group (WG), a part of the 3Rs Translational and Predictive Sciences (TPS) Leadership Group of the International Consortium for Innovation and Quality in Pharmaceutical Development (IQ Consortium), to better understand the provision of supportive care on nonclinical studies. The survey aimed to define supportive care strategies, identify alternatives to supportive care, and understand regulatory feedback and implications about supportive care decisions. The survey was distributed to members of the 3Rs Leadership Group of the IQ Consortium and several CRO partners, representing 35 organizations as potential respondents. The results of the survey from 13 respondents provided positive feedback that helped in highlighting the existing best practices for supportive care. Areas of enhancements identified included greater consistency in the inclusion of sponsor veterinarians on project teams for externalized studies, the timing of initiation of supportive care, and increased sharing of regulatory outcomes. Suggested best practices include creating a plan of action for veterinary care prior to study start, and enhancing information sharing regarding expected toxicities from previous study findings. Improved communication regarding supportive care will pave the way for enhanced 3Rs initiatives, refining the existing animal care paradigm and helping to ensure the most ethical toxicology study designs.

Strategies to encourage the adoption of social housing during cardiovascular telemetry recordings in non-rodents

The National Centre for the Replacement, Refinement and Reduction of Animals in Research (NC3Rs) is working with industry to promote social housing during cardiovascular telemetry recordings within non-rodent safety pharmacology and toxicology studies. Following surveys to capture current practice, benefits and concerns to adoption of this refinement (2015 and 2017), a 2018 European workshop shared experience and practical advice to address common barriers such as sensitivity of different study designs and the potential for cross-contamination with test article in socially-housed conditions. A similar number of responses were received to each survey (38 in 2015; 36 in 2017), from biopharmaceutical companies and CROs that perform or outsource non-rodent telemetry studies. Each dataset had different respondents, but 19 facilities provided answers regarding dogs and non-human primates (NHPs) for both surveys. More respondents socially-housed their non-rodents in 2017; increases were apparent for both the non-recording/acclimatisation periods and the telemetry recording periods compared with 2015. However, on recording days only 60, 75 and 89% of respondents from Europe and 25, 14 and 36% of respondents from outside of Europe socially-housed their dogs, minipigs or NHPs respectively. The potential for contamination with test article between animals housed together is considered by some facilities as justification for individual housing during recordings, however, survey data did not support this rationale. Nine organisations provided data on prevalence of vomiting during telemetry studies, showing the risk was moderate for dogs and very low for minipig and NHP. Further, if vomiting did occur, this could be managed effectively with little impact on study outcomes or validity and with careful dose selection, the risk is further diminished. A recent increase in published papers and posters on this topic would suggest many more companies are planning, or have recently implemented, this refinement. The continued willingness of the community to share practical experience and publish validation data may lead to this approach becoming the 'new standard' across the industry in the near future, representing a core component of 'best-practice' recommendations to increase animal welfare whilst maintaining quality data provision for investigational and regulatory purposes.

Justification for species selection for pharmaceutical toxicity studies

Toxicity studies using mammalian species are generally required to provide safety data to support clinical development and licencing registration for potential new pharmaceuticals. International regulatory guidelines outline recommendations for the order (rodent and/or non-rodent) and number of species, retaining flexibility for development of a diverse range of drug modalities in a manner relevant for each specific new medicine. Selection of the appropriate toxicology species involves consideration of scientific, ethical and practical factors, with individual companies likely having different perspectives and preferences regarding weighting of various aspects dependent upon molecule characteristics and previous experience of specific targets or molecule classes. This article summarizes presentations from a symposium at the 2019 Annual Congress of the British Toxicology Society on the topic of species selection for pharmaceutical toxicity studies. This symposium included an overview of results from a National Centre for the Replacement, Refinement and Reduction of Animals in Research (NC3Rs) and Association of British Pharmaceutical Industry (ABPI) international collaboration that reviewed the use of one or two species in regulatory toxicology studies and justification for the species selected within each programme. Perspectives from two pharmaceutical companies described their processes for species selection for evaluation of biologics, and justification for selection of the minipig as a toxicological species for small molecules. This article summarizes discussions on the scientific justification and other considerations taken into account to ensure the most appropriate animal species are used for toxicity studies to meet regulatory requirements and to provide the most value for informing project decisions.

INSPIRE: A European training network to foster research and training in cardiovascular safety pharmacology

Safety pharmacology is an essential part of drug development aiming to identify, evaluate and investigate undesirable pharmacodynamic properties of a drug primarily prior to clinical trials. In particular, cardiovascular adverse drug reactions (ADR) have halted many drug development programs. Safety pharmacology has successfully implemented a screening strategy to detect cardiovascular liabilities, but there is room for further refinement. In this setting, we present the INSPIRE project, a European Training Network in safety pharmacology for Early Stage Researchers (ESRs), funded by the European Commission's H2020-MSCA-ITN programme. INSPIRE has recruited 15 ESR fellows that will conduct an individual PhD-research project for a period of 36 months. INSPIRE aims to be complementary to ongoing research initiatives. With this as a goal, an inventory of collaborative research initiatives in safety pharmacology was created and the ESR projects have been designed to be complementary to this roadmap. Overall, INSPIRE aims to improve cardiovascular safety evaluation, either by investigating technological innovations or by adding mechanistic insight in emerging safety concerns, as observed in the field of cardio-oncology. Finally, in addition to its hands-on research pillar, INSPIRE will organize a number of summer schools and workshops that will be open to the wider community as well. In summary, INSPIRE aims to foster both research and training in safety pharmacology and hopes to inspire the future generation of safety scientists.

Opportunities to Apply the 3Rs in Safety Assessment Programs

Before a potential new medicine can be administered to humans it is essential that its safety is adequately assessed. Safety assessment in animals forms an integral part of this process, from early drug discovery and initial candidate selection to the program of recommended regulatory tests in animals. The 3Rs (replacement, reduction, and refinement of animals in research) are integrated in the current regulatory requirements and expectations and, in the EU, provide a legal and ethical framework for in vivo research to ensure the scientific objectives are met whilst minimizing animal use and maintaining high animal welfare standards. Though the regulations are designed to uncover potential risks, they are intended to be flexible, so that the most appropriate approach can be taken for an individual product. This article outlines current and future opportunities to apply the 3Rs in safety assessment programs for pharmaceuticals, and the potential (scientific, financial, and ethical) benefits to the industry, across the drug discovery and development process. For example, improvements to, or the development of, novel, early screens (e.g., in vitro, in silico, or nonmammalian screens) designed to identify compounds with undesirable characteristics earlier in development have the potential to reduce late-stage attrition by improving the selection of compounds that require regulatory testing in animals. Opportunities also exist within the current regulatory framework to simultaneously reduce and/or refine animal use and improve scientific outcomes through improvements to technical procedures and/or adjustments to study designs. It is important that approaches to safety assessment are continuously reviewed and challenged to ensure they are science-driven and predictive of relevant effects in humans.

Recalibration of nonclinical safety pharmacology assessment to anticipate evolving regulatory expectations

Safety pharmacology (SP) has evolved in terms of architecture and content since the inception of the SP Society (SPS). SP was initially focused on the issue of drug-induced QT prolongation, but has now become a broad spectrum discipline with expanding expectations for evaluation of drug adverse effect liability in all organ systems, not merely the narrow consideration of torsades de pointes (TdP) liability testing. An important part of the evolution of SP has been the elaboration of architecture for interrogation of non-clinical models in terms of model development, model validation and model implementation. While SP has been defined by mandatory cardiovascular, central nervous system (CNS) and respiratory system studies ever since the core battery was elaborated, it also involves evaluation of drug effects on other physiological systems. The current state of SP evolution is the incorporation of emerging new technologies in a wide range of non-clinical drug safety testing models. This will refine the SP process, while potentially expanding the core battery. The continued refinement of automated technologies (e.g., automated patch clamp systems) is enhancing the scope for detection of adverse effect liability (i.e., for more than just IKr blockade), while introducing a potential for speed and accuracy in cardiovascular and CNS SP by providing rapid, high throughput ion channel screening methods for implementation in early drug development. A variety of CNS liability assays, which exploit isolated brain tissue, and in vitro electrophysiological techniques, have provided an additional level of complimentary preclinical safety screens aimed at establishing the seizurogenic potential and risk for memory dysfunction of new chemical entities (NCEs). As with previous editorials that preface the annual themed issue on SP methods published in the Journal of Pharmacological and Toxicological Methods (JPTM), we highlight here the content derived from the most recent (2015) SPS meeting held in Prague, Czech Republic. This issue of JPTM continues the tradition of providing a publication summary of articles primarily presented at the SPS meeting with direct bearing on the discipline of SP. Novel method development and refinement in all areas of the discipline are reflected in the content.