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NC3Rs | 20 Years: Pioneering Better Science

Dr Fiona Sewell

Head of Toxicology
Portrait of Dr Fiona Sewell

Fiona leads our programmes on toxicology and regulatory sciences. She is a member of the Science and Technology Group.

View Fiona's Office-led projects

External Roles

  • Executive Committee of the British Toxicology Society (BTS)
  • Member of PrecisionTox Horizon 2020 Scientific Advisory Board 
  • Member of the UK Health Security Agency AWERB
  • Steering committee member of the Health and Environmental Science (HESI) Transforming the Evaluation of Agrochemicals (TEA) project
  • Member of the European Centre for Ecotoxicology and Toxicology of Chemicals (ECETOC) Task Force on Dose Selection

NC3Rs publications

Sewell F et al. (2024). New supporting data to guide the use of evident toxicity in acute oral toxicity studies (OECD TG 420). Regulatory Toxicology and Pharmacology. 146:105517. doi: 10.1016/j.yrtph.2023.105517

Burden N et al. (2023). An international cross-laboratory survey on fish vitellogenin analysis: Methodological challenges and opportunities for best practice. Regulatory Toxicology and Pharmacology. 145:105501 doi: 10.1016/j.rtph.2023.105501 

Bishop P et al. (2023). Challenges and Opportunities for Overcoming Dog Use in Agrochemical Evaluation and Registration. ALTEX. 40(3):534-540. doi: 10.14573/altex.2302151

Prior H et al. (2023). The use of recovery animals in nonclinical safety assessment studies with monoclonal antibodies: further 3Rs opportunities remain. Regulatory Toxicology and Pharmacology. 138:105339. doi: 10.1016/j.yrtph.2023.105339

Chien HT et al. (2023). Re-evaluating the need for chronic toxicity studies with therapeutic monoclonal antibodies, using a weight of evidence approach. Regulatory Toxicology and Pharmacology. 138:105329. doi: 10.1016/j.yrtph.2022.105329 

Wolf D et al. (2022). Transforming the evaluation of agrochemicals. Pest Manag Sci. 78(12):5049-5056. doi: 10.1002/ps.7148

Sewell F et al. (2022). Recommendations on Dose Level Selection for Repeat Dose Toxicity Studies. Archives of Toxicology. 96(7):1921-1934. doi: 10.1007/s00204-022-03293-3

Prior H et al. (2022). Exploring the Definition of "Similar Toxicities": Case Studies Illustrating Industry and Regulatory Interpretation of ICH S6(R1) for Long-Term Toxicity Studies in One or Two Species. International Journal of Toxicology. 10915818221081439. doi: 10.1177/10915818221081439

Sewell F et al. (2021). Rethinking agrochemical safety assessment: A perspective. Regulatory Toxicology and Pharmacology, 105068. doi: 10.1016/j.yrtph.2021.105068

Sewell F et al. (2021). Preclinical screening for antidepressant activity - shifting focus away from the Forced Swim Test to the use of translatinal biomarkers. Regulatory Toxicology and Pharmacology, 125:105002. doi: 10.1016/j.yrtph.2021.105002

Prior H et al. (2021). Refining procedures within regulatory toxicology studies: improving data and animal welfare. Animals, 11(11):3057. doi: 10.3390/ani11113057

Burden N et al. (2021). Investigating endocrine-disrupting properties of chemicals in fish and amphibians: Opportunities to apply the 3Rs. Integrated Environmental Assessment and Management, online ahead of print. doi: 10.1002/ieam.4497

Tan et al. (2021). Opportunities and challenges related to saturation of toxicokinetic processess: inplications for risk assessment. Regulatory Toxicology and Pharmacology, 127:105070. doi: 10.1016/j.yrtph.2021.105070 

LaLone et al. (2021). Global consortium to advance cross speicies extrapolation f the effects of chemicals in regulatory toxicology. Environmental Toxicology and Chemistry, 40(12):3226-3233. doi: 10.1016/j.yrtph.2021.105029.

Katsiadaki I et al. (2021). Dying for change: A roadmap to refine the fish acute toxicity test after 40 years of applying a lethal endpoint. Ecotoxicology and Environmental Safety, 223:112585. doi: 10.1016/j.ecoenv.2021.112585

ECETOC Guidance on dose selection. Technical report 138, Brussels, March 2021. ISSN-2079-1526-138 (online). 

Prior H et al. (2020). Justification for species selection for pharmaceutical toxicity studies. Toxicology Research, 9: 758-770. doi: 10.1093/toxres/tfaa081

Burden, N et al. (2021) Opportunities and challenges for integrating new in vitro methodologies in hazard testing and risk assessment. Small, 17(15):e2006298 doi: 10.1002/smll.202006298

Sewell F et al.  (2020). Use of the kinetically-derived maximum dose: Opportunities for delivering 3Rs benefits. Regulatory Toxicology and Pharmacology, 116: 104734. doi: 10.1016/j.yrtph.2020.104734

Prior H et al. (2020).  Opportunities for use of one species for longer-term toxicology testing during drug development: a cross-industry evaluation. Regulatory Toxicology and Pharmacology, 113: 104624. doi: 10.1016/j.yrtph.2020.104624

Luijten M et al. (2020). A comprehensive view on mechanistic approaches for cancer risk assessment of non-genotoxic agrochemicals. Regulatory Toxicology and Pharmacology, 118:10478. doi: 10.1016/j.yrtph.2020.104734 

Clements JM et al. (2020). Predicting the safety of medicines in pregnancy: A workshop report. Reproductive Toxicology, 93:199-210. doi: 10.1016/j.reprotox.2020.02.011

Rivetti C et al. (2020). Vision of a near future: Bridging the human health-environment divide. Toward an integrated strategy to understand mechanisms across species for chemical saftey assessment. Toxicology In Vitro, 62:104692. doi: 10.1016/j.tiv.2019.104692

Gellatly N and Sewell F (2019). Regulatory acceptance of in silico approaches for the safety assessment of cosmetic-related substances. Computational Toxicology, 11: 82-89. doi: 10.1016/j. comtox.2019.03.003

Prior H et al. (2019). Reflections on the progress towards non-animal methods for acute toxicity testing of chemicals.  Regulatory Toxicology and Pharmacology, 102: 30-33. doi: 10.1016/j.yrtph.2018.12.008.  

Sewell F et al. (2018). An evaluation of the fixed concentration procedure for assessment of acute inhalation toxicity. Regulatory Toxicology and Pharmacology, 94: 22-32. doi: 10.1016/j.yrtph.2018.01.001.

Sewell F et al. (2018). The future trajectory of adverse outcome pathways: a commentary. Archives of Toxicology, 92(4): 1657-1661. doi: 10.1007/s00204-018-2183-2.

Prior H et al. (2017). Overview of 3Rs opportunities in drug discovery and development using non-human primates. Drug Discovery Today: Disease Models, 23:11-16. doi: 10.1016/j.ddmod.2017.11.005

Sewell F et al. (2017). Steps towards the international regulatory acceptance of non-animal methodology in safety assessment. Regulatory Toxicology and Pharmacology, 89: 50-56. doi: 10.1016/j.yrtph.2017.07.001.

Sewell F et al. (2017). The current status of exposure-driven approaches for chemical safety assessment: A cross-sector perspective. Toxicology, 389: 109-117. doi: 10.1016/j. tox.2017.07.018.

Sewell F et al. (2017). Challenges and opportunities for the future use of monoclonal antibody development: improving safety assessment and reducing animal use. mAbs, 9(5): 742-755. doi: 10.1080/19420862.2017.1324376.

Sewell F et al. (2016). Opportunities to apply the 3Rs in safety assessment programs. Institute for Laboratory Animal Research Journal, 57(2): 234-245. doi: 10.1093/ilar/ilw024.

Sewell F et al. (2015) A global initiative to refine acute inhalation studies through the use of 'evident toxicity' as an endpoint: Towards adoption of the fixed concentration procedure.  Regulatory Toxicology Pharmacology, 73(3):770-9. doi:10.1016/j.yrtph.2015.10.018.

Burden N et al. (2015). Pioneering better science through the 3Rs: An introduction to the National Centre for the Replacement, Refinement, and Reduction of Animals in Research (NC3Rs). Journal of the American Association for Laboratory Animal Science, 54(2):198-208. PMCID: PMC4382625

Burden N et al. (2015). Testing chemical safety: What is needed to ensure the widespread application of non-animal approaches? PLoS Biology, 13(5):e1002156 doi:10.1371/journal.pbio.1002156

Burden N et al. (2015) Adverse outcome pathways can drive non-animal approaches for safety assessment. Journal of Applied Toxicology, 35(9):971-975. doi: 10.1002/jat.3165

Sewell F et al. (2014). Recommendations from a global cross-company data sharing initiative on the incorporation of recovery phase animals in safety assessment studies to support first-in-human clinical trials. Regulatory Toxicology and Pharmacology, 70(1):413-29. doi: 10.1016/j.yrtph.2014.07.018

Chapman et al. (2013). A global pharmaceutical company initiative: An evidence based approach to define the upper limit of body weight loss in short term toxicity studies. Regulatory Toxicology and Pharmacology, 67(1)27-38. doi: 10.1016/j.rtph.2013.04.003 

For additional publications, see Fiona's ResearchGate profile.


UK and European Registered Toxicologist (ERT)
Accredited since 2019

MSc Applied Toxicology
University of Surrey, 2017

PhD, Molecular Biology 
University of Leeds, 2005 - 2009
Therapeutic targeting of Fibroblast Growth Factor Receptor 3 (FGFR3) in urothelial cell carcinoma.