Considerations from an International Regulatory and Pharmaceutical Industry (IQ MPS Affiliate) Workshop on the Standardization of Complex In Vitro Models in Drug Development

In May 2022, there is an International Regulatory and Pharmaceutical Industry (Innovation and Quality [IQ] Microphysiological Systems [MPS] Affiliate) Workshop on the standardization of complex in vitro models (CIVMs) in drug development. This manuscript summarizes the discussions and conclusions of this joint workshop organized and executed by the IQ MPS Affiliate and the United States Food and Drug Administration (FDA). A key objective of the workshop is to facilitate discussions around opportunities and/or needs for standardization of MPS and chart potential pathways to increase model utilization in the context of regulatory decision making. Participation in the workshop included 200 attendees from the FDA, IQ MPS Affiliate, and 26 global regulatory organizations and affiliated parties representing Europe, Japan, and Canada. It is agreed that understanding global perspectives regarding the readiness of CIVM/MPS models for regulatory decision making and potential pathways to gaining acceptance is useful to align on globally. The obstacles are currently too great to develop standards for every context of use (COU). Instead, it is suggested that a more tractable approach may be to think of broadly applicable standards that can be applied regardless of COU and/or organ system. Considerations and next steps for this effort are described.

OECD workshop consensus report: Ethical considerations with respect to human derived products, specifically human serum, in OECD test guidelines

The ethical needs and concerns with use and sourcing of human materials, particularly serum, in OECD in vitro test guidelines were explored in a dedicated international workshop held in 2019. The health-related aspects of the donation procedure, including tissue screening, donor health, laboratory work health protection, permission from the donor for commercial use, payment of the donors and the potential for exploitation of low-income populations and data protection of the donors; supply, availability, and competition with clinical needs; traceability of the serum and auditability/GLP needs for the Test Guideline Programme, were examined. Here we provide the recommendations of the workshop with respect to the use of human serum, and potentially other human reagents, specifically with regard to test method development for OECD Test Guideline utility as part of the Mutual Acceptance of Data requirement across all OECD member countries. These include informed donor consent terminology, a checklist of human serum information requirements to be included with the Good Laboratory Practise report, and suitable sources for human serum to ensure waste supplies are used, that can no longer be used for medical purposes, ensuring no competition of supply for essential medical use.

Reactive Oxygen Species in the Adverse Outcome Pathway Framework: Toward Creation of Harmonized Consensus Key Events

Reactive oxygen species (ROS) and reactive nitrogen species (RNS) are formed as a result of natural cellular processes, intracellular signaling, or as adverse responses associated with diseases or exposure to oxidizing chemical and non-chemical stressors. The action of ROS and RNS, collectively referred to as reactive oxygen and nitrogen species (RONS), has recently become highly relevant in a number of adverse outcome pathways (AOPs) that capture, organize, evaluate and portray causal relationships pertinent to adversity or disease progression. RONS can potentially act as a key event (KE) in the cascade of responses leading to an adverse outcome (AO) within such AOPs, but are also known to modulate responses of events along the AOP continuum without being an AOP event itself. A substantial discussion has therefore been undertaken in a series of workshops named "Mystery or ROS" to elucidate the role of RONS in disease and adverse effects associated with exposure to stressors such as nanoparticles, chemical, and ionizing and non-ionizing radiation. This review introduces the background for RONS production, reflects on the direct and indirect effects of RONS, addresses the diversity of terminology used in different fields of research, and provides guidance for developing a harmonized approach for defining a common event terminology within the AOP developer community.

POS1096 THE EFFECT OF ONE DRY NEEDLING SESSION ON PAIN AND CENTRAL PAIN PROCESSING IN PATIENTS WITH KNEE OSTEOARTHRITIS: A RANDOMIZED CONTROLLED TRIAL

Background:

Osteoarthritis (OA) is the leading cause of chronic disability in the elderly1,2. Abnormal central pain processing (CPP) is present in around 30% of the knee OA patients3 and can be partly induced by peripheral nociception through long term potentiation4. An attempt to resolve abnormal CPP can be to eliminate this nociception5. Myofascial trigger points (MTrPs) are often present in knee OA6, can lead to nociception7 and therefore abnormal CPP if prolonged present8. These are usually defined as hypersensitive tender spots within taut bands of a muscle9. Additionally, both MTrPs and knee OA can induce disturbed motor control, increased co-antagonist activation and modified gait pattern10,11. Dry needling (DN) is often used to deactivate the MTrP and thus resolve the source of nociception, which normally results in reducing pain and restoring muscle dysfunction12. However, studies about the effect of DN on CPP and other outcomes than pain are very limiting. Therefore, more high-quality studies concerning DN and its effects on CPP, muscle features and gait are needed13,14.

Objectives:

The aim of this randomized controlled trial is to assess the effect of one DN session compared to one sham needling (SN) session on pain (processing), muscle activity and gait in patients with knee OA.

Methods:

61 patients participated of which 31 were allocated to the DN and 30 to the SN group. Each patient underwent one treatment session. Primary outcomes were pain intensity, measured with questionnaires; and CPP, measured with quantitative sensory testing. Secondary outcomes included muscle co-activation, measured with electromyography; and spatiotemporal parameters, measured with gait analysis. Patients were assessed at baseline, 15 minutes (post 1) and 3 days after intervention (post2- only for the outcome pain). Linear mixed models was used to identify the possible differences over time between the two therapy modalities.

Results:

The following significant within group differences were observed: decreased pain, stride- and step time and increased widespread pain pressure threshold and step length. A significant between group difference of the conditioned pain modulation score was found, whereas the SN group showed a decrease in difference between the pain pressure threshold scores (with and without conditioning stimulus) and the DN group remained stable. No other significant between or within group differences were detected. However, if we compared both interventions, the change over time for the visual analogue scale (VAS) behaved different in the DN (p<0.05, post 2 - baseline) and SN group (p<0.05, post 1 - baseline and post 2 - post 1).

Conclusion:

One DN session has no larger effect on all outcome measurements compared to SN. Both therapies seem to be useful to improve pain and widespread pain pressure threshold in short term, however the improvement of pain differs in the groups. Although improvements in some spatiotemporal parameters were observed, it is uncertain they are of clinical relevance or related to treatment. More research is necessary to reveal the ideal number of sessions of DN to improve outcomes and to reveal the effect of DN compared to no treatment, as SN could have hide the real treatment effect.

References:

[1]Reginster, J. Y. Rheumatol. Oxf. 41 Supp 1, 3–6 (2002)

[2]Lespasio, M. J. et al. Perm J 21, 16–183 (2017)

[3]Lluch, E. et al. Eur J Pain 18, 1367–75 (2014)

[4]Mease, P. J. et al. J. Rheumatol. 38, 1546–1551 (2011)

[5]Nijs, J. et al. Expert Opin Pharmacother 15, 1671–83 (2014)

[6]Bajaj, P. et al. J. Musculoskelet. Pain 9, 17–33 (2001)

[7]Jafri, M. S. Int. Sch. Res. Not. 2014, (2014)

[8]Cagnie, B. et al. Curr Pain Headache Rep 17, 348 (2013)

[9]Borg-Stein, J. et al. Arch. Phys. Med. Rehabil. 83, S40–S47 (2002)

[10]Childs, J. D. et al. Clin. Biomech. 19, 44–9 (2004)

[11]Ibarra, J. M. et al. J Pain 12, 1282–8 (2011)

[12]Rahou-El-Bachiri, Y. et al. J. Clin. Med. 9, (2020)

[13]Stieven, F. F. et al. J. Manipulative Physiol. Ther. (2021)

[14]Dor, A. et al. J Bodyw Mov Ther 21, 642–647 (2017)

Figure 1.

Mean and standard error of VAS scores over time in the DN and SN group

Acknowledgements:

I like to thank and acknowledge the contribution of the other executive researchers (Lise Brosens, Ayoub El Bouchaoni, Ben Ceusters, Sven Huybrechts and Mathias Van Loon), the participated dry needling therapists, Dry Needling Ghent, Trigger and the University Hospital of Antwerp.

Disclosure of Interests:

None declared.

Bringing together scientific disciplines for collaborative undertakings: a vision for advancing the adverse outcome pathway framework

BACKGROUND

Decades of research to understand the impacts of various types of environmental occupational and medical stressors on human health have produced a vast amount of data across many scientific disciplines. Organizing these data in a meaningful way to support risk assessment has been a significant challenge. To address this and other challenges in modernizing chemical health risk assessment, the Organisation for Economic Cooperation and Development (OECD) formalized the adverse outcome pathway (AOP) framework, an approach to consolidate knowledge into measurable key events (KEs) at various levels of biological organisation causally linked to disease based on the weight of scientific evidence (http://oe.cd/aops). Currently, AOPs have been considered predominantly in chemical safety but are relevant to radiation. In this context, the Nuclear Energy Agency's (NEA's) High-Level Group on Low Dose Research (HLG-LDR) is working to improve research co-ordination, including radiological research with chemical research, identify synergies between the fields and to avoid duplication of efforts and resource investments. To this end, a virtual workshop was held on 7 and 8 October 2020 with experts from the OECD AOP Programme together with the radiation and chemical research/regulation communities. The workshop was a coordinated effort of Health Canada, the Electric Power Research Institute (EPRI), and the Nuclear Energy Agency (NEA). The AOP approach was discussed including key issues to fully embrace its value and catalyze implementation in areas of radiation risk assessment.

CONCLUSIONS

A joint chemical and radiological expert group was proposed as a means to encourage cooperation between risk assessors and an initial vision was discussed on a path forward. A global survey was suggested as a way to identify priority health outcomes of regulatory interest for AOP development. Multidisciplinary teams are needed to address the challenge of producing the appropriate data for risk assessments. Data management and machine learning tools were highlighted as a way to progress from weight of evidence to computational causal inference.

A comprehensive view on mechanistic approaches for cancer risk assessment of non-genotoxic agrochemicals

Currently the only methods for non-genotoxic carcinogenic hazard assessment accepted by most regulatory authorities are lifetime carcinogenicity studies. However, these involve the use of large numbers of animals and the relevance of their predictive power and results has been scientifically challenged. With increased availability of innovative test methods and enhanced understanding of carcinogenic processes, it is believed that tumour formation can now be better predicted using mechanistic information. A workshop organised by the European Partnership on Alternative Approaches to Animal Testing brought together experts to discuss an alternative, mechanism-based approach for cancer risk assessment of agrochemicals. Data from a toolbox of test methods for detecting modes of action (MOAs) underlying non-genotoxic carcinogenicity are combined with information from subchronic toxicity studies in a weight-of-evidence approach to identify carcinogenic potential of a test substance. The workshop included interactive sessions to discuss the approach using case studies. These showed that fine-tuning is needed, to build confidence in the proposed approach, to ensure scientific correctness, and to address different regulatory needs. This novel approach was considered realistic, and its regulatory acceptance and implementation can be facilitated in the coming years through continued dialogue between all stakeholders and building confidence in alternative approaches.

Chemical carcinogen safety testing: OECD expert group international consensus on the development of an integrated approach for the testing and assessment of chemical non-genotoxic carcinogens

While regulatory requirements for carcinogenicity testing of chemicals vary according to product sector and regulatory jurisdiction, the standard approach starts with a battery of genotoxicity tests (which include mutagenicity assays). If any of the in vivo genotoxicity tests are positive, a lifetime rodent cancer bioassay may be requested, but under most chemical regulations (except plant protection, biocides, pharmaceuticals), this is rare. The decision to conduct further testing based on genotoxicity test outcomes creates a regulatory gap for the identification of non-genotoxic carcinogens (NGTxC). With the objective of addressing this gap, in 2016, the Organization of Economic Cooperation and Development (OECD) established an expert group to develop an integrated approach to the testing and assessment (IATA) of NGTxC. Through that work, a definition of NGTxC in a regulatory context was agreed. Using the adverse outcome pathway (AOP) concept, various cancer models were developed, and overarching mechanisms and modes of action were identified. After further refining and structuring with respect to the common hallmarks of cancer and knowing that NGTxC act through a large variety of specific mechanisms, with cell proliferation commonly being a unifying element, it became evident that a panel of tests covering multiple biological traits will be needed to populate the IATA. Consequently, in addition to literature and database investigation, the OECD opened a call for relevant assays in 2018 to receive suggestions. Here, we report on the definition of NGTxC, on the development of the overarching NGTxC IATA, and on the development of ranking parameters to evaluate the assays. Ultimately the intent is to select the best scoring assays for integration in an NGTxC IATA to better identify carcinogens and reduce public health hazards.

The adverse outcome pathway concept: A basis for developing regulatory decision-making tools

The Adverse Outcome Pathway (AOP) concept is expected to guide risk assessors in their work to use all existing information on the effects of chemicals on humans and wildlife, and to target the generation of additional information to the regulatory objective. AOPs will therefore be used in the Organisation for Economic Co-operation and Development (OECD) chemical safety programme, as underlying scientific rationales for the development of alternative methods for hazard assessment, such as read-across, in vitro test methods or the development of integrated testing strategies that have the potential to replace animal tests. As a proof-of-concept, the OECD has developed an AOP for skin sensitisation, and as a follow-up has: a) implemented the AOP into the OECD QSAR Toolbox, so that information related to the Key Events (KEs) in the AOP can be used to group chemicals that are expected to act by the same mechanism and hence have the same skin sensitisation potential; b) developed alternative test methods for the KEs, so that ultimately chemicals can be tested for skin sensitisation without the use of animal tests. The development of integrated testing strategies based on the AOP is ongoing. Building on this proof-of-concept, the OECD has launched an AOP development programme with a first batch of AOPs published in 2016. A number of IT tools, which together form an AOP Knowledge Base, are at various stages of development, and support the construction of AOPs and their use in the development of integrated approaches for testing and assessment. Following the publication of the first batch of AOPs, OECD member countries will decide on priorities for their use in supporting the development of tools for regulatory use.

International STakeholder NETwork (ISTNET): creating a developmental neurotoxicity (DNT) testing road map for regulatory purposes

A major problem in developmental neurotoxicity (DNT) risk assessment is the lack of toxicological hazard information for most compounds. Therefore, new approaches are being considered to provide adequate experimental data that allow regulatory decisions. This process requires a matching of regulatory needs on the one hand and the opportunities provided by new test systems and methods on the other hand. Alignment of academically and industrially driven assay development with regulatory needs in the field of DNT is a core mission of the International STakeholder NETwork (ISTNET) in DNT testing. The first meeting of ISTNET was held in Zurich on 23-24 January 2014 in order to explore the concept of adverse outcome pathway (AOP) to practical DNT testing. AOPs were considered promising tools to promote test systems development according to regulatory needs. Moreover, the AOP concept was identified as an important guiding principle to assemble predictive integrated testing strategies (ITSs) for DNT. The recommendations on a road map towards AOP-based DNT testing is considered a stepwise approach, operating initially with incomplete AOPs for compound grouping, and focussing on key events of neurodevelopment. Next steps to be considered in follow-up activities are the use of case studies to further apply the AOP concept in regulatory DNT testing, making use of AOP intersections (common key events) for economic development of screening assays, and addressing the transition from qualitative descriptions to quantitative network modelling.

A retrospective performance assessment of the developmental neurotoxicity study in support of OECD test guideline 426

OBJECTIVE

We conducted a review of the history and performance of developmental neurotoxicity (DNT) testing in support of the finalization and implementation of Organisation of Economic Co-operation and Development (OECD) DNT test guideline 426 (TG 426).

INFORMATION SOURCES AND ANALYSIS

In this review we summarize extensive scientific efforts that form the foundation for this testing paradigm, including basic neurotoxicology research, interlaboratory collaborative studies, expert workshops, and validation studies, and we address the relevance, applicability, and use of the DNT study in risk assessment.

CONCLUSIONS

The OECD DNT guideline represents the best available science for assessing the potential for DNT in human health risk assessment, and data generated with this protocol are relevant and reliable for the assessment of these end points. The test methods used have been subjected to an extensive history of international validation, peer review, and evaluation, which is contained in the public record. The reproducibility, reliability, and sensitivity of these methods have been demonstrated, using a wide variety of test substances, in accordance with OECD guidance on the validation and international acceptance of new or updated test methods for hazard characterization. Multiple independent, expert scientific peer reviews affirm these conclusions.