Workshop series to identify, discuss, and develop recommendations for the optimal generation and use of in vitro assay data for tobacco product regulation. - Project Summary/Abstract
Research priorities for the Center for Tobacco Products (CTP) include “toxicological assays (in vivo and in
vitro) to compare toxicity across different types of tobacco products within the same class, including electronic
nicotine delivery systems (ENDS), cigars, waterpipes, and smokeless tobacco.” Although CTP regulatory
guidance documents include genotoxicity and other in vitro assays in the types of toxicity information required
for submissions, there is no standardized guidance or regulatory approved methods for the evaluation of
various tobacco products, including ENDS. Therefore, the Institute for In Vitro Sciences (IIVS), a 501(c)(3)
nonprofit organization, has organized a Workshop Series to identify, discuss and develop recommendations for
the best scientific/technical approaches for generating and interpreting in vitro assay data for comparing
toxicity within and across tobacco product classes. Designed as true working meetings, expert stakeholders
will discuss and develop recommendations that will then be published. The initial focus of the series has been
on the regulatory genetic toxicology assays (Ames test, in vitro mammalian assays for cytogenetic damage
and gene mutation). Going forward there will be an increasing emphasis on human disease models. These
workshops provide a unique opportunity for multiple stakeholders to share their expertise and will provide
published resources that regulatory agencies, academic laboratories, and industry may use as they address
the public health issues related to the use of tobacco products. Some of workshop reports may serve as
authoritative publications that can be referenced for optimal methodologies and data interpretation. So far, the
workshops have identified important issues for using in vitro assays for evaluating tobacco products, and have
focused on several of CTP’s high-priority topics. Multiple working groups have been established to collect
background information, to hold discussions between workshops, to draft manuscripts, and to develop
recommendations that are presented and discussed during the workshops. Consensus statements have
resulted from these workshops. Two manuscripts have been published and two are in preparation. For
upcoming workshops additional background documents are in preparation by working groups. Methods for
generating aerosols for in vitro cell exposure and quantitative approaches to comparing toxicity potency will be
the focus of a virtual workshop in April 2021. Workshops for October 2021 and April 2022 are now planned.
Working groups are discussing and preparing background manuscripts with a focus on ENDS products and, in
addition, (1) methods for dosimetry, (2) recommendations for the Ames test, and (3) recommendations for the
mouse lymphoma gene mutation assay. Also included will be approaches for evaluating both general toxicity
and disease-causing potential of tobacco products using 3-D respiratory models,
