Abstract 3094: Biophysics in kinase drug discovery programs: Spectral shift technology from fragment screening to mechanism of action

Abstract Using Eurofins Discovery’s state-of-the art Hit-Finding platform, our experts designed an optimized screening cascade combining cutting-edge High-throughput Screening (HTS) technologies with the latest Biophysics techniques. With advanced technologies, such as the Echo® MS and RapidFire MS for HTS, and SPR, MST, TSA, nanoDSF and ITC for Biophysics, the cascade is effective for primary screening, orthogonal assays and evaluating Mechanism of Action (MoA). There are many biophysical approaches which bring value to drug discovery programs, and it is the target properties which drive the selection of the most suitable technology. In this presentation, we will highlight the novel Spectral Shift technology, one of the techniques employed by the Dianthus (well-known for the MST-TRIC). The goal was to rapidly implement an assay that monitors the ability of PIM3 to bind to ATP, as well as to compounds and fragments in solution. Using the Echo MS’ acoustic-droplet ejection, nanoliter dispensing in 394-well plates, robust data by Spectral Shift were quickly generated for the fragment-based screening campaign. Hits were confirmed in Dose-response with µM-range affinity values (KD), and TSA was used as an orthogonal assay for the identification of stabilizers among the selected PIM3 binders. For a defined set of 826 proprietary fragments, a single dose screening at 600µM using Spectral Shift was run, leading to the identification of 11% of potential binders. The 100 fragments were then confirmed in dose-response titration and 80 binders were confirmed. The top 30 binders were selected for orthogonal characterization using TSA. This led to the selection of the top 6 confirmed fragments, on which a MoA study in MST-TRIC was performed. Following this evaluation, 3 allosteric binders were identified, with KD from 355 to 550µM (affinity of orthosteric binders from 55 to 333µM). Biophysics plays an important role in drug discovery by qualifying valuable assets and increasing the success rates of future Hit-finding programs. The fragment hits selected in this PIM3 Kinase project, which show ADP-Glo™ activities, are now ready for crystallography studies (NMR & X-ray co-crystallization). Citation Format: Celine Legros, Vanessa Porkolab, Maud Sigoillot, Olivier Mirguet. Biophysics in kinase drug discovery programs: Spectral shift technology from fragment screening to mechanism of action [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3094.