An article published on November 23, 2017 by the regulatory news provider Chemical Watch reported on the issues discussed at a recent workshop held by the U.S. National Academies of Sciences (NAS), titled “Understanding pathways to a paradigm shift in toxicity testing and decision making.” Workshop participants demonstrated, on the example of non-animal assays for skin toxicity, that the alternative assays “give better predictions of human toxicity than the local lymph node assay (LLNA) in rodents.” Further, the issues with “the relevance and variability of animal test results,” as well as “the need to understand the uncertainties associated with alternative test models,” were highlighted.
Anna Lowit, co-chair of the U.S. Interagency Coordinating Committee on the Validation of Alternative Methods (ICCVAM), speaking of “progress in moving away from rodent tests for skin irritants,” said that “industry partners are working towards actually eliminating the 28-day and 90-day rat inhalation study, just because it’s not really relevant to humans.” She further stated that “we can do better with animal 3D tissues combined with sophisticated pharmacokinetic modeling and just avoid the animal completely”. Lowit concluded that “when we start to tackle complicated things, like cancer and developmental reprotoxicity, we will have enough experience under our belt, in a way that we won’t have to hold up the rat and the mouse models as a gold standard.”
The challenges of substituting complex animal tests with alternative systems are, however, still far from being solved. A report on the regulatory applicability of non-animal approaches, prepared by the European Chemicals Agency (ECHA) and published on November 22, 2017, concluded that “more progress [is] needed to replace animal tests under EU chemicals laws.” ECHA summarized that “for lower tier endpoints such as skin corrosion/irritation, serious eye damage/eye irritation and skin sensitization, companies already use in vitro tests as the default methods.” However, “for more complex endpoints, for example repeated dose toxicity or reproductive toxicity, non-animal approaches are not yet foreseeable.” ECHA further stated that “new approaches, such as in vitro microsystems and high-throughput/high-content methods . . . require further standardization and validation before they can be accepted for regulatory use.”
Chemical Watch (November 23, 2017). “U.S. NAS workshop raises issue of animal tests as ‘gold standard.’”
ECHA (November 22, 2017). “More progress needed to replace animal tests under EU chemical laws.”
Chemical Watch (November 23, 2017). “ECHA: Non-animal tests for complex endpoints remain distant.”