Skip Navigation

Evidence-Based Toxicology Collaboration

Staff

Katya Tsaioun

Katya Tsaioun
Director

Prior to joining the EBTC, Dr. Tsaioun was at Safer Medicines Trust, a UK patient safety charity with the mission of improving patients’ safety by advancing new in vitro and in silico safety tests into regulatory use. She has formed collaborations with US EPA and FDA, and has built a scientific advisory panel with cross-Atlantic stakeholders consisting of technology companies, academic groups, regulatory authorities, and other non-profit organizations. Prior to that Dr. Tsaioun ran a company Apredica, specializing in in vitro ADME and safety assessment. She led the company into becoming a leader in early non-animal safety assessment. Prior to founding Apredica, Dr. Tsaioun managed safety assessment programs for pharmaceutical companies.

Dr. Tsaioun serves on the scientific review boards and study sections of the NIH and disease foundations and is a frequent invited speaker at international conferences. She wrote numerous book chapters and articles and co-edited a book, ADMET for Medicinal Chemists (Wiley & Sons, 2011). She earned her PhD from Tufts University in Human Nutrition Science in 1999.

Martin Stephens

Martin Stephens
Founding Director

Martin L. Stephens is a senior research associate at the Johns Hopkins Center for Alternatives to Animal Testing (CAAT), where he promotes new methods in toxicology and new approaches to assessing their performance. He is the founding director—and currently a member of the Secretariat—of the Evidence-based Toxicology Collaboration, which seeks to translate evidence-based approaches from medicine to toxicology.

Prior to joining Johns Hopkins University in 2011, Dr. Stephens was vice president for animal research issues at The Humane Society of the United States. He served on the National Academy of Sciences’ committee that produced the landmark report, Toxicity Testing in the 21st Century: A Vision and a Strategy. He co-founded AltTox, a website devoted to non-animal methods of toxicity testing. He currently serves on the board of directors of Chimp Haven, a congressionally mandated sanctuary for former laboratory chimpanzees. Dr. Stephens has received the Society of Toxicology Enhancement of Animal Welfare Award, the Humane Society of the United States’ Russell and Burch Award, the Doerenkamp-Zbinden Award, and the CAAT Recognition Award for his contributions to alternative methods and animal protection. He received a PhD in biology from The University of Chicago.

Sebastian Hoffmann

Sebastian Hoffman
Research Staff, European Affairs

Sebastian Hoffmann is running the independent consultancy ‘seh consulting + services‘ in Paderborn, Germany, since 2009, specialised in validation and assessment of in vitro test methods and in the regulation of chemicals (REACH) and cosmetic ingredients. He has been supporting the EBTC secretariat since 2011. He worked for the European Centre for the Validation of Alternative Methods (ECVAM) of the European Commission for five years, contributing inter alia to the management of validation studies of in vitro tests. His research activities focus on methodological challenges in the assessment of in vitro tests, the design and evaluation of integrated testing strategies and the application of evidence-based approaches to toxicology. He is an appointed member of the European Commission’s Scientific Committee on Occupational Exposure Limits. Dr. Hofmann is a statistician by training. He received his Ph.D. from the University of Konstanz (Germany) in 2005 for his thesis ‘Evidence-based in vitro toxicology.’

Gbeminiyi Samuel

Gbeminiyi Samuel
Postdoctoral Fellow

Gbeminiyi Samuel is an assistant researcher at the Johns Hopkins Center for Alternatives to Animal Testing (CAAT), where he adapts, identifies, and promotes methods from evidence-based medicine and health care (EBM/HC) that are applicable to evidence-based toxicology. He is a member of the Methods Work Group of the Evidenced-based toxicology Collaboration (EBTC), involved in promoting and developing guidance on all aspects of evidence-based assessments, including study quality appraisal, toxicological test method performance, and chemical effects on human and environmental health.

Prior to joining the EBTC in 2012, he worked as graduate research assistant with Prof. Breysse at the Center for Childhood Asthma in Urban Environment, where he facilitated sampling preparation for exposure assessment and control of endotoxins and particulates. Dr. Samuel was awarded the American Industrial Hygiene Foundation Scholarship in 2011 for his promising efforts in the field of occupational and environmental health. He earned his medical (MBBS) degree from University of Lagos (Nigeria) in 2007. He received his master’s degree in occupational and environmental hygiene from the Johns Hopkins Bloomberg School of Public Health in 2012. Dr. Samuel is currently in residency training in internal medicine at the Howard University Hospital.

Alexandra Maertens

Alexandra Maertens
Postdoctoral Fellow

Alexandra Maertens is a post-doctoral fellow at the Center for Alternatives to Animal Testing where she provides bioinformatics support for the Mapping the Human Toxome project as well as working on the Zebrafish project at the EBTC. Alexandra received her PhD from Johns Hopkins with Dr. Hartung serving as her advisor, focusing on the application of data mining to systems toxicology and alternative testing strategies. She is also active in promoting Green Toxicology—the idea of implementing toxicology considerations into the design process of industrial chemicals—which was the subject of a recent symposium at Johns Hopkins and a session at the 2015 Society of Toxicology meeting.