51st Annual Meeting & ToxExpo - Society of Toxicology

Society of Toxicology 2012
Scientific
Roundtables
Tuesday
Regulatory Science: Bridging the
Gap between Discovery and Product
Availability
Evolving the EPA Endocrine Disruptor Screening
Program: From Using High-Throughput Screening
Assays for Prioritization to Reducing Reliance on
Whole Animal Tests
Tuesday, March 13, 12:00 Noon to 1:20 PM
Chairperson(s): Richard Judson, US EPA, Research Triangle Park,
NC, and Vicki L. Dellarco, US EPA, Washington, DC.
Sponsor:
Reproductive and Developmental Toxicology Specialty Section
Endorsed by:
In Vitro and Alternative Methods Specialty Section
Testing has begun as part of the EPA Endocrine Disruptor Screening
Program (EDSP) Tier 1 battery of 11 in vitro and in vivo tests. A
recognized issue with the EDSP is that the current Tier 1 screening
battery is highly resource intensive in terms of cost, time, and animal
usage for the large numbers of chemicals with unknown endocrine
potential that need to be evaluated. The significant advances in both
computational and molecular technologies have enabled a more
rapid identification of markers for adverse outcome pathways since
EPA began work on developing and implementing the EDSP. The
EPA is proposing to evolve the EDSP by incorporating in vitro highthroughput
screening (HTS) assays that can rapidly detect potential
interactions of chemicals with the estrogen, androgen, thyroid
hormone, and steroidogenesis (EATS) pathways. In the near term,
incorporating HTS assays will focus on developing a prioritized list
of chemicals for evaluation in the current Tier 1 battery. Prioritization
would continue to take other factors into account, including exposure
and use. A longer term goal is to evolve the Tier 1 battery by fully
incorporating HTS assays in order to increase reliance on nonanimal
screens for which there is confidence in their ability to predict
in vivo adverse effects. Although the overall approach is reasonable, it
is highly provocative and debatable for a number of reasons. On the
one hand, this proposal has the potential to greatly improve the speed,
cost effectiveness, and mechanistic specificity of the EDSP using
fewer animals, but on the other hand, there are concerns about reliability
and relevance of the HTS assays and lack of full validation (e.g.,
transferability between laboratory evaluation) metabolic capacity, etc.
Our panel of experts will present the case for and against using this
approach and will allow time for open discussion with the audience.
• High-Throughput Endocrine Pathway Assays Are Ready for
Testing Thousands of Chemicals. Richard Judson, US EPA,
Research Triangle Park, NC.
The Thematic Track information can be found on pages 8–9.
• One View from Industry on the Promises and Challenges of
Using HTS Assays in EDSP. Sue Marty, Dow Chemical Company,
Midland, MI.
• A View from the EPA Regulatory Offices on the Promises and
Challenges of Using HTS Assays in the EDSP. Vicki L. Dellarco,
US EPA, Washington, DC.
• HTS Assays Covering Key Pathways Covered by EDSP Tier 1
Do Not Yet Exist. Thomas Zoeller, University of Massachusetts,
Amherst, MA.
Regulatory Science: Bridging the
Gap between Discovery and Product
Availability
Improving Chemical Safety Assessment through
Harmonization: Why, How, and When?
Tuesday, March 13, 12:00 Noon to 1:20 PM
Chairperson(s): Haitian Lu, Dow AgroSciences LLC, Indianapolis,
IN, and Michael Holsapple, Battelle, Columbus, OH.
Sponsor:
Regulatory and Safety Evaluation Specialty Section
Endorsed by:
American Association of Chinese in Toxicology
Special Interest Group
Global Strategy Task Force
Risk Assessment Specialty Section
Chemical safety assessment for the protection of human health is
not harmonized globally. Toxicology data requirements and test
guidelines that differ across geographies could result in repetition
of studies and therefore waste of animals and resources. The other
prominent difference is that although exposure and risk assessment
are critical components of well-established regulatory frameworks,
the chemical safety regulations differ in several emerging geographies
and heavily rely on hazard-based approaches. What also remains to
be discussed is how more harmonized approaches for risk assessment
can be achieved globally, considering potential geographic differences
in exposure scenarios, and the utility of hazard-based approaches
under certain circumstances. A roundtable session on opportunities
for more harmonized paradigms and practices of chemical safety
assessment is both important and timely as emerging geographies are
becoming increasingly influential in the global economy, and several
of them are actively developing their regulatory frameworks. This
session intends to provide a unique opportunity for stakeholders from
all over the world, including regulators from emerging geographies,
to review the current status, exchange views on the challenges and
opportunities, dialogue on potential solutions on the basis of sound
science in toxicology and risk assessment, and brainstorm on a path
forward. Overall, this session seeks to facilitate the participants to
reach mutual understanding of current challenges and opportunities,
Thematic Session
100
SOT’s 51 st Annual Meeting