New Approaches to Drug and Chemical Safety Assessment
Submitting InstitutionUniversity of Dundee
Unit of AssessmentClinical Medicine
Summary Impact TypePolitical
Research Subject Area(s)
Medical and Health Sciences: Pharmacology and Pharmaceutical Sciences
Summary of the impact
The development of new paradigms for toxicity testing has benefitted the
Scottish economy and population in Tayside through two biotechnology
companies which, between them, employ up to 40 staff and have had a
combined turnover of some £15M over the last five years. The benefits
extend to the international pharmaceutical, cosmetic, chemical and
consumer product industries, which have gained access to innovative new
methods for safety testing at a time of acute need for more predictive
methods to evaluate drug safety and better in vitro tests for
consumer products. Patients and consumers in Europe and worldwide have
benefitted indirectly from improved risk assessment of drugs, consumer
products and environmental contaminants.
The research underpinning this impact was led by Prof. C. Roland Wolf
(at the time Director, Biomedical Research Centre; now Director, Medical
Research Institute; Ninewells Hospital and Medical School Dundee) and used
biotechnology approaches to develop better models for the study of
xenobiotic disposition and toxicity. Its aim was to address differences
between humans and commonly-used rodent models in terms of responses to
xenobiotics and to create in vitro systems which can be used to
accelerate drug development and reduce candidate attrition in clinical
Research published in 1997 developed new technology for the heterologous
expression of functional human cytochrome P450s (P450s) in bacteria, yeast
and mammalian cells [i]. The proteins thus generated are used to predict
pathways of drug disposition and toxicity, making the safety assessment of
drug candidates more predictive of likely outcomes in humans. Cell lines
expressing P450s can be used in bioreactors to generate human-specific
metabolites, with significant cost savings over what are often challenging
chemical syntheses. This work resulted in patents granted worldwide and to
the establishment in 1998 of the spinout company Cypex.
The aim of the second phase of this research was to develop novel in
vivo approaches for the assessment of drug and chemical safety by
generating transgenic reporter models in which processes such as oxidative
stress can be visualised by histochemical staining [ii] and/or the
synthesis of excretable reporter molecules. The results and know-how from
this programme were central to the creation in 2002 of the spinout
company, CXR Biosciences (CXR).
One of the primary aims of the ongoing collaboration between Dundee
Medical School and CXR has been to create genetically-engineered models
which can be used to improve the predictivity of human risk assessments.
Among the first of these was the Hepatic Reductase Null™ mouse [iii] in
which the entire hepatic P450 system is ablated in adult mice allowing the
dependence of metabolic and toxic processes on P450-dependent hepatic
metabolism to be evaluated.
Of particular note has been the collaboration between the Medical School,
CXR, ITI Life Sciences and TaconicArtemis, Cologne which led to the
generation of a unique panel of transgenic mouse models humanised for
pathways of drug metabolism [iv,v]. By replicating entire pathways of
Phase One human drug metabolism in mice, the profound species differences
in these pathways were circumvented, allowing more informed predictions of
human drug responses to be obtained, accelerating the process of drug
development and benefitting the pharmaceutical industry by reducing the
proportion of drug candidates which undergo costly failure late in
Work in the Medical School has also generated cell-line based reporter
systems for the detection of oxidative stress and associated modes of
toxicity. These include the human-derived reporter cell line AREc32 [vi],
which contains a luciferase gene construct controlled by the antioxidant
response element and responds robustly to compounds such as the
redox-cycling agent tert-butylhydroquinone which disrupt cellular
oxidation status. Such cell lines offer the possibility that the safety of
substances such as cosmetic ingredients can, in future, be evaluated
without animal testing (http://ec.europa.eu/enterprise/epaa/3_events/3_3_workshops/18-llna-taalman.pdf).
References to the research
• Prof John Hayes, Dr Colin Henderson and Dr Michael Pritchard,
Biomedical Research Centre, Ninewells Hospital & Medical School,
• Prof Bruce Whitelaw, Division of Developmental Biology, The Roslin
Institute, University of Edinburgh.
• Dr Nico Scheer, TaconicArtemis GmbH, Cologne, Germany.
i. Pritchard MP, Ossetian R, Li DN, Henderson CJ, Burchell B, Wolf
CR and Friedberg T (1997) A general strategy for the expression of
recombinant human cytochrome P450s in Escherichia coli using bacterial
signal peptides: expression of CYP3A4, CYP2A6 and CYP2E1. Arch.
Biochem. Biophys. 345, 342-354 (DOI:
ii. Young R, Wolf CR, Brown K, Hayes JD and Whitelaw CB (2010)
Spatial monitoring of toxicity in HMOX-LacZ transgenic mice. Transgenic
Res. 19, 897-902 (DOI: 10.1007/s11248-010-9363-z).
iii. Henderson CJ, Otto DME, Carrie D, Magnuson MA, McLaren AW, Rosewell
I and Wolf CR (2003) Inactivation of the hepatic cytochrome P450
system by conditional deletion of hepatic cytochrome P450 reductase. J.
Biol. Chem. 278, 13480-13486 (DOI: 10.1074/jbc.M212087200).
iv. Scheer N, Ross J, Rode A, Zevnik B, Niehaves S, Faust N and Wolf
CR (2008) A novel panel of mouse models to evaluate the role of human
pregnane X receptor and constitutive androstane receptor in drug response.
J. Clin. Invest. 118, 3228-3239 (DOI: 10.1172/JCI35483).
v. Scheer N, Kapelyukh Y, McEwan J, Beuger V, Stanley LA, Rode A and Wolf
CR (2011) Modelling human cytochrome P450 2D6 metabolism and drug-drug
interaction by a novel panel of knockout and humanized mouse lines. Mol.
Pharm. 81, 63-72 (DOI: 10.1124/mol.111.075192).
vi. Wang XJ, Hayes JD and Wolf CR (2006) Generation of a stable
antioxidant response element-driven reporter gene cell line and its use to
show redox-dependent activation of nrf2 by cancer chemotherapeutic agents.
Cancer Res. 66, 10983-10994 (DOI:
• Wolf CR et al: MRC/BBSRC-funded LINK P450 Programme;
Industry Sponsors: Astra, Glaxo, Janssen Pharmaceutica, Lilly, Novo
Nordisk, Parke-Davis, Pfizer, Roche Products, Sanofi-Winthrop, Servier,
SmithKline Beecham, Wellcome, Wyeth (1993-1998) £3.5M.
• Wolf CR et al: The Toxicology Consortium; Industry
Sponsors: AstraZeneca, Eli Lilly, GlaxoSmithKline, Novartis, Pfizer,
Roche, Wyeth (1998-2005) £6.0M.
• CXR Biosciences and TaconicArtemis: ITI Life Sciences Transgenic
Screening and Safety Models (TSM/TSE); Scottish Enterprise (2005-2009)
• Wolf CR et al: MARCAR; EU Innovative Medicines
Initiative Award (2010-2015) Total budget €25M; €12M in kind from
industrial sponsors; Dundee component £1.1M.
• Wolf CR: REDOX; European Research Council Senior Investigator
Award (2011-2016) £2.1M.
• Wolf CR, Friedberg TH and Pritchard MP: Cytochrome P450
expression in enterobacteria; Patent Numbers EP0914446, US6566108,
CA22559619; assigned to British Technology Group (BTG).
• Wolf CR and Henderson CJ: Transgenic animals for assessing drug
metabolism and toxicity in man; Patent Numbers EP1711051, US2009013417.
Patents owned by Imperial Cancer Research Technology; licensed to CXR and
five pharmaceutical companies which participated in the Toxicology
• Wolf CR and Henderson CJ: Modulation of cytochrome P450
reductase activity; Patent Numbers EP1521827, EP2065464, US7700822,
CA2403235, JP005532807, GB2391231. Patents owned by Imperial Cancer
• Wolf CR and Clark AJ: Methods and kits for drug screening and
toxicity testing using promoter-reporter cells derived from embryonic stem
cells; Patent Number EP1893749, US2006292694, US2006292695, US2008152632,
CA2613529,JP2008546417. Patents owned by CXR Biosciences/Geron
Details of the impact
This research has benefitted the Scottish economy and local population
through the establishment of two biotechnology companies, Cypex and CXR
which, between them, employ up to 40 staff and generate an average annual
turnover of £2.4M. Professor Wolf, a Director of CXR from its
formation until August 2012 and a member of the Scientific Advisory Group
of the Translational Medicine Research Initiative, received the OBE in
2010 for his contribution to life sciences in Scotland.
Cypex (www.cypex.co.uk) was formed
in 1998 and has, since releasing its first recombinant P450 in 2000,
developed a portfolio of >100 products including 19 human P450s, eight
sulphotransferases, murine and canine P450s, fine chemicals and
antibodies. These are marketed in Europe via Tebu-Bio , in the US via
XenoTech LLC and in Asia and Africa. Their use helps pharmaceutical
companies to eliminate drug candidates which are likely to fail during
development or cause drug-drug interactions in patients. Cypex also offers
contract services in custom protein expression and the production of drug
metabolites. Its products (in the form of cell lines which express human
P450s) are used in bioreactors to generate drug metabolites in sufficient
quantities for toxicological evaluation, as is now required by the FDA
when human-specific metabolites represent more than 10% of the
administered dose . This application has been adopted by pharmaceutical
companies including Novartis and Hoffmann-La Roche ; the intellectual
property has been licensed to BTG for further commercialisation and
Novartis has licensed the technology (£400K) for further marketing and
was formed in 2002 to provide services in preclinical drug development and
chemical safety. It currently has >60 clients worldwide and has
pioneered the application of humanised mouse models in drug development.
It opened its first international sales office in the USA in May 2012 .
It also markets a number of cell lines and other reagents derived from
University-based research [ii,iii,vi]; these include the Hepatic Reductase
Null™ mice and a range of reporter mice, licensed for marketing by CXR via
Taconic in the USA and Europe. AstraZeneca, Pfizer and Nestlé have also
taken out licenses to these models.
The second aspect of the impact of this research has had international
reach, benefitting the pharmaceutical industry and regulators. This aspect
arose from an ITI Life Sciences-sponsored research and development
programme (2005-2009) in which CXR and TaconicArtemis GmbH (Cologne)
collaborated in the generation of humanised mouse models to determine the
human-specific systemic effects of drugs and chemicals [iv,v]. The
generation of these exciting new research tools, which are now marketed
via Taconic [6,7], has been welcomed by pharmaceutical companies and
regulators because of their applicability in drug regulatory submissions
These models have important applications in, for example, allowing the
species specificity of non-genotoxic carcinogenesis to be established
. This is central to the predictive risk assessment of drugs and
consumer products; to that end the use of these humanised and reporter
models is embedded in the EU Innovative Medicines Initiative programmes
and DILI (http://www.imi.europa.eu/content/mip-dili),
whose aim is to identify new biomarkers to predict the effects of
non-genotoxic carcinogens and predict the potential for drug-induced liver
injury. CXR is a key small/medium enterprise participant in this €25M
collaboration, led by Dundee, between academia, the pharmaceutical
industry and drug regulators, and the extent of industrial involvement
(>€5M) is a direct result of the Dundee team's track record in
developing commercially-applicable novel models for assessing chemical
In a third aspect of impact, this research has benefitted industry,
patients and consumers in Europe and beyond as a result of the development
of innovative methods for in vitro toxicity testing. Better in
vitro testing methods are urgently needed as a result of the
enactment in 2007 of the REACH regulations, which demand toxicity testing
of some 30,000 substances using non-animal methods wherever possible, and
the staged implementation of the 7th Amendment to the EU Cosmetics
Directive, which has prohibited the use of animals for skin irritation,
corrosion, and genotoxicity testing since 2009 and for characterising the
disposition of cosmetic ingredients since March 2013. The AREc32 cell line
[iv], licensed via CXR to Givaudan, has been shown to be useful as part of
an integrated testing strategy for the prediction of chemical-induced skin
hypersensitivity reactions without the need for animal testing [9,10] and
has been adopted for water quality assessment and the evaluation of
disinfection by-products by institutions in Australia and Germany .
The use of this cell line provides the pharmaceutical, cosmetic, consumer
product and chemicals industries with a cost-effective,
legally-permissible method for assessing potential skin sensitisers and
benefits patients and consumers by improving safety assessments.
Sources to corroborate the impact
- Example press release dated 24-Oct-08 at http://www.prlog.org/10132610-tebu-bio-and-cypex-ltd-introduce-seven-new-dog-bactosomes.html.
- Cypex-Xenotech product brochure at http://188.8.131.52/uploaded/documents/Cypex.pdf.
- FDA Guidance for Industry Safety Testing of Drug Metabolites (February
- Letter of corroboration from PTDCA Biocatalysis Department, F.
Hoffmann-La Roche Ltd.
- Press release dated 17-May-12; http://www.cxrbiosciences.com/news_article.php?news_id=43.
- tADMET™: A unique and evolving portfolio of translational
(humanized & knockout) mouse models, in vitro tools and
services for an improved prediction of the Absorption, Distribution,
Metabolism, Excretion and Toxicity
characteristics of new compounds in humans.
- Letter of corroboration from TaconicArtemis GmbH, Cologne, Germany.
- Ross J, Plummer SM, Rode A, Scheer N, Bower CC, Vogel O, Henderson CJ,
Wolf CR and Elcombe CR (2010) Human constitutive androstane
receptor (CAR) and pregnane X receptor (PXR) support the hypertrophic
but not the hyperplastic response to the murine nongenotoxic
hepatocarcinogens phenobarbital and chlordane in vivo. Toxicol. Sci.
116, 452-66 (DOI: 10.1093/toxsci/kfq118).
- Natsch A, Emter R and Ellis G (2009) Filling the Concept with Data:
Integrating Data from Different In Vitro and In Silico
Assays on Skin Sensitizers to Explore the Battery Approach for
Animal-Free Skin Sensitization Testing Toxicol. Sci. 107,
- Presentation by Joanna Matheson, US Consumer Product Safety
Commission, "OECD Dermal Sensitization AOP: Regulatory Perspective" on
the US Environmental Protection Agency website; http://www.epa.gov/oppfead1/cb/ppdc/testing/2013/july/workshop/session2-oecd.pdf.
- Escher BI, van Daele C, Dutt M, Tang JYM and Altenburger R (2013) Most
Oxidative Stress Response In Water Samples Comes From Unknown Chemicals:
The Need For Effect-Based Water Quality Trigger Values. Environ.
Sci. Technol. 47, 7002 -7011 (DOI: