Derek Nexus contains expert-derived functionality for assessment of the skin sensitisation endpoint. Lhasa’s new web application ‘skin sensitisation defined approach ITSv1 1.0’, combines an in silico prediction from Derek Nexus with results from two OECD-validated in chemico/in vitro assays (DPRA and h-CLAT)1,2 to provide hazard and potency skin sensitisation predictions, without the use of animal tests.
What can you expect from this web application?
The defined approach (DA) generates a Derek skin sensitisation prediction for a chemical of interest, including an assessment of whether the prediction is in domain for the purposes of the DA.
The application also calculates Lipophilicity, this information is combined with the h-CLAT outcome to ensure any negative assay results are applicable, based on the information provided in OECD test guideline 442E.2
The tool then assigns a score to each applicable/in domain information source and combines these to generate an overall hazard classification (skin sensitiser or non-sensitiser) and where appropriate, a potency sub-classification (UN GHS 1A or UN GHS 1B). An inconclusive outcome is provided if insufficient information sources are available.
The ITSv1 DA has been evaluated using…
• 168 chemicals with Local Lymph Node Assay (LLNA) data – it correctly identified the hazard classification for 87% of the dataset, and the GHS potency sub-classification for 71% of the dataset.3
• 66 chemicals with human data – it correctly predicted hazard and potency for 86% and 68% of the dataset, respectively.
For comparison, the LLNA correctly predicted the known human hazard and potency classifications 82% and 60% of the time. In all cases only a small proportion of chemicals (3-6%) gave an inconclusive prediction when assessed using the ITSv1 DA.
For existing Derek Nexus users, access Skin Sensitisation Defined Approach ITSv1 1.0 here.
Interested in discovering how Lhasa can assist your hazard and potency skin sensitisation predictions? Get in touch with us to find out more!
- OECD (2021), Test No. 442C: In Chemico Skin Sensitisation: Assays addressing the Adverse Outcome Pathway key event on covalent binding to proteins, OECD Guidelines for the Testing of Chemicals, Section 4, OECD Publishing, Paris, https://doi.org/10.1787/9789264229709-en
- OECD (2018), Test No. 442E: In Vitro Skin Sensitisation: In Vitro Skin Sensitisation assays addressing the Key Event on activation of dendritic cells on the Adverse Outcome Pathway for Skin Sensitisation, OECD Guidelines for the Testing of Chemicals, Section 4, OECD Publishing, Paris, https://doi.org/10.1787/9789264264359-en
- OECD (2021), Guideline No. 497: Defined Approaches on Skin Sensitisation, OECD Guidelines for the Testing of Chemicals, Section 4, OECD Publishing, Paris, https://doi.org/10.1787/b92879a4-en