CeeTox announced positive results from a validation study of their SenCeeTox skin sensitization assay conducted by VITO-ABS. The study, funded by PETA, accurately predicted the ability of 10 blinded chemicals to cause sensitization and their potency in 9 out of 10 chemicals. This represents an important step towards validating a non-animal replacement for regulatory use in identifying skin sensitizers. Further validation studies will be conducted by Cosmetics Europe to submit results to EURL ECVAM for regulatory acceptance.

1. 4717 Campus Drive, Kalamazoo, MI 49008 269.353.5555 (P) 269.544.1077 (F) www.ceetox.com
CeeTox Announces Positive Results of Ring Trial for PETA-Funded SenCeeTox®
Non-Animal Skin
Allergy Assay
For Immediate Release:
CeeTox Contact: Ms. Jean Harden (jharden@ceetox.com) +1-269-372-8711)
PETA Contact: (U.K.) Dr. Gilly Stoddart (gillys@peta.org.uk; +44 (0)20 7837 6327)
(U.S.) Dr. Amy Clippinger (AmyJC@peta.org; 610-701-8605)
August 9, 2013
Kalamazoo, Mich. --- CeeTox today reports the positive results of a recent phase of a PETA-funded validation
study performed by the Flemish Institute for Technological Research (VITO)’s Applied BIO & Molecular
Systems (ABS) team. The study confirms the ability of a second laboratory to perform CeeTox’s SenCeeTox®
skin sensitization assay to correctly classify chemicals as sensitizers or non-sensitizers.
The SenCeeTox assay stands out from other non-animal assays – and even certain animal-based ones – in that it
can categorize chemicals according to their potency. The results of the SenCeeTox trial conducted at VITO-
ABS accurately predicted the ability to elicit a sensitization reaction for all 10 blinded compounds tested.
Furthermore, it predicted the exact sensitization potency category for 9 out of the 10 compounds, classifying the
10th
compound by only a one potency category difference.
CeeTox transferred the method for its SenCeeTox assay to VITO-ABS’s laboratory in Belgium as part of a
blinded ring-trial funded by PETA U.K. Ring-trials are used to ensure that one laboratory’s results can be
successfully replicated in other laboratories. This represents the first nongovernmental organization (NGO)-
funded validation study of a non-animal method for regulatory use.
After initial training, CeeTox provided VITO-ABS with a blinded set of 10 compounds. VITO-ABS tested the
compounds in its lab and provided the data to CeeTox. The data were run through the proprietary CeeTox
algorithm to predict an expected sensitization potency level, unblinded, and then compared to expected results.
Because the results from the SenCeeTox assay have been so promising, further validation of this assay will be
continued by Cosmetics Europe, after which all results will be submitted to the European Union Reference
Laboratory for alternatives to animal testing (EURL ECVAM).
How SenCeeTox predicts sensitization
Three dimensional, human, reconstructed epidermis (RHE) tissues are treated with multiple concentrations of
each test article. This RHE skin model accurately replicates barrier properties, and possesses many of the key
functional traits, signaling pathways and metabolic enzymes of normal human skin. After incubation, the skin
tissues are then tested to assess the cytotoxic effect and reactivity of the test substances as well as gene
expression of key genes along the Nrf2/Keap1/ARE signaling pathway, the activation of which leads to skin
sensitization.

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Finally, the data are analyzed using a proprietary algorithm to predict the chemical’s likelihood of causing a
human sensitization reaction.
Importance of the test
“This PETA-funded trial is an important step toward validating a reliably predictive full replacement non-
animal test for regulatory use,” says Tim Mitchell, president of CeeTox, Inc.
Jessica Sandler, director of PETA U.S.’s Regulatory Testing Division, says “We are excited to be the first
animal rights organization involved in the validation of a non-animal test method and to move the science
forward to save tens of thousands of mice and guinea pigs from painful skin sensitization testing.”
Validation of this testing method is particularly timely in light of the ban on sales of cosmetics in Europe that
have been tested on animals. Additionally, this test is important in light of the 2018 REACH deadline which
will require a large number of chemicals to be tested for their ability to induce skin sensitization.
About CeeTox
CeeTox, founded in 2003, is a contract research organization (CRO) focused on in vitro toxicity and safety
screening of new products including cosmetics, personal care products, agricultural and household chemicals,
and drug candidates. In vitro typically refers to a test that is performed in a cell model instead of in or on an
animal. For more information, please visit www.ceetox.com.
About PETA
People for the Ethical Treatment of Animals (PETA) is an affiliate of PETA US, the largest animal rights
organization in the world, which has more than three million members and supporters. PETA focuses its
attention on the four areas in which the largest numbers of animals suffer the most intensely for the longest
periods of time: on factory farms, in the clothing trade, in laboratories, and in the entertainment industry. For
more information, please visit www.peta.org.uk.
About VITO – team ABS
VITO is an independent research and technology organization (RTO) providing innovative solutions to
stimulate sustainable development. ABS offers (i) R&D: biological and molecular methods for human health
diagnostics and biomonitoring (ii) Validation of alternative biological test methods and (iii) GLP/non-GLP
contract testing. For more information, please visit www.vito.be.