AstraZeneca R&D Gothenburg, Vastra Gotaland, Sweden
Abstract: In the realm of drug discovery, validating hits derived from DNA-encoded library (DEL) screening is an indispensable step. This process necessitates the resynthesis and retesting of compounds to ascertain the consistency of observed activity while mitigating experimental artifacts. However, the complexity arises from the fact that DNA barcodes in DEL libraries encode synthetic routes rather than chemical structures. This intricacy often leads to challenges in identifying genuine actives, primarily due to incomplete chemical transformations during encoding, resulting in low validation rates. In response, we will present a comprehensive strategy for DEL hit validation. We will elucidate our approach, which prominently features on-DNA compound resynthesis, mirroring the methods employed during initial library synthesis. This seamlessly integrates with subsequent hit validation endeavors including a combination of high-sensitivity surface-based biosensing and high-resolution mass spectrometry techniques. We will illustrate affinity correlations between on-DNA and off-DNA compounds, offer insights into assay development, and emphasize the utilization of enhanced sensitivity to allow us to detect low-abundancy on-DNA compounds. We will describe a systematic framework for DEL hit validation, enhancing the identification of genuine binders with unwavering confidence and heightened sensitivity for drug discovery.