NAMs for evaluating DART potential

New approach methodologies for evaluating DART potential: Review on state of the art, applicability domain and coverage of developmental stages

M. Burbank 1, N. Hewitt 2, F. Gautier 3, A. Noel-Voisin 3, N. Golbamaki 1, R. Grall 1, M. Léonard 4, L. Carron 3, T. Bringel 1, S. Emery 1, L. Guillet-Revol 1, N. De Croze 1, G. Ouédraogo 1

1 L'Oréal Research and Innovation, Aulnay sous Bois, France

2 SWS, Erzhausen, Germany

3 L'Oréal Research and Innovation, Saint-Ouen, France

4 Experconnect, Paris, France

All cosmetic related ingredients mandate safety evaluation under use conditions, a requirement enforced by European regulatory demands since 2013. These assessments increasingly utilize New Approach Methodologies (NAMs). Given that developmental and reproductive effects (DART) are critical regulatory endpoints, predictive DART NAMs are crucial for maintaining high safety standards and innovation of new ingredients.

This recent review investigated established in silico and in vitro NAMs for DART assessment of cosmetic-related ingredients, examining their coverage of DART Adverse Outcome Pathways, Key Characteristics, and relevant biomarkers to pinpoint gaps. It encompassed a brief look at in silico models and an in-depth analysis of 17 established in vitro NAMs. It found that while multiple in silico tools exist for early DART screening and data gap filling, all stages of male and female fertility and embryo-fetal development are covered by at least one of the 17 evaluated NAMs, with a primary focus on late organogenesis. Many NAMs specifically measure receptors, enzymes, and pathways involved in teratogenicity, reflecting an enhanced understanding of underlying mechanisms. Cellular endpoint assays are being improved with biomarker measurements, and these can be integrated into Weight of Evidence approaches across different testing tiers. The zebrafish embryotoxicity test was identified as the most frequently cited NAM in the literature. This analysis concluded that available NAMs effectively enable the analysis of various DART stages.

L'Oréal exemplifies this progress by developing an innovative Integrated Testing Strategy (ITS) to assess chemical teratogenic potential. This multimodal approach combines in silico predictions (OECD QSAR Toolbox DART model), in vitro assays (devTox quickPredict™), and Zebrafish Embryotoxicity Tests. By covering different developmental stages and biological organizational levels, this ITS provides a comprehensive evaluation. Combining results using a "2 out of 3 rule," L'Oréal's strategy achieves a high sensitivity of 96% and a good specificity of 71.4%, ensuring reliable hazard identification.