Abstract 938: Screening the entire kinase-directed, FDA-approved pharmacopeia against the largest collection of wild-type and mutant kinases reveals many opportunities for drug repurposing and targeted therapy

Abstract We sought to screen all FDA approved, cancer-indicated, kinase targeting drugs using the gold standard radiometric biochemical activity assay (HotSpot) against the largest collection of kinases in the world (100 drugs against 735 total kinases including 395 wild type and 340 mutants). Virtually every drug examined exhibits polypharmacology inhibiting many kinases. Rarely does the intended target represent the greatest inhibition observed from a drug. Furthermore, most drugs inhibit a select group of mutant kinases, including especially mutants of kinases distinct from the intended target. Within a given kinase, each cancer-identified mutation is often as distinct as the different wild-type kinases are from each other, in terms of inhibition profile. Considering mutants, then, the cancer-relevant druggable kinome is many thousand distinct targets, not 518 “plus a few”. Exposing this reality is a first step towards developing all the therapeutic tools necessary to ultimately defeat cancer. Here, we reveal vast and specific repurposing opportunities among the existing pharmacopeia for tumors that are driven by kinases not previously recognized as targets for certain drugs, and for tumors that have become chemotherapy-resistant through mutation of specific kinases. The most exciting and clinically relevant opportunities were confirmed in cell-based assays, results of which will also be presented. Citation Format: Christian M. Loch, Shuguang Liang, Jianghong Wu, Mia Eason, Alison Goupil, Anthony Acinapura, Jamie Purcell, Maia Dominguez. Screening the entire kinase-directed, FDA-approved pharmacopeia against the largest collection of wild-type and mutant kinases reveals many opportunities for drug repurposing and targeted therapy 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 (6Suppl): Abstract nr 938.