Cell December 23, 2025

Mapping cellular targets of covalent cancer drugs in the entire mammalian body

Available online 22 December 2025 In Press, Corrected Proof Short article Mapping cellular targets of covalent cancer drugs in the entire mammalian body Author links open overlay panel , , , , , , , , , , , , , , , , , , https://doi.org/10.1016/j.cell.2025.11.030 Get rights and content Under a Creative Commons license Open access Highlights • Copper saturation and repeated reactions enabled 3D whole-body click labeling • vCATCH enabled unbiased and registered drug-binding profiling in the mouse brain • vCATCH revealed cellular binding of covalent cancer drugs across the adult mouse body Summary As our understanding of biological systems reaches single-cell and high spatial resolutions, it becomes imperative that pharmacological approaches match this precision to understand drug actions. This need is particularly urgent for the targeted covalent inhibitors that are currently re-entering the stage for cancer treatments. By leveraging the unique kinetics of click reactions, we developed volumetric clearing-assisted tissue click chemistry (vCATCH) to enable deep and homogeneous click labeling across the three-dimensional (3D) mammalian body. With simple and passive incubation steps, vCATCH offers cellular-resolution drug imaging in the entire adult mouse. We combined vCATCH with hydrogel-based reinforcement of three-dimensional imaging solvent-cleared organs (HYBRiD) imaging and virtual reality to visualize and quantify in vivo targets of two clinical cancer drugs, afatinib and ibrutinib, which recapitulated their known pharmacological distribution and revealed previously unreported tissue and cell-type engagement potentially linked to off-target effects. vCATCH provides a body-wide, unbiased platform to map covalent drug engagements at unprecedented scale and precision. Graphical abstract Download: Download high-res image (227KB) Download: Download full-size image Keywords drug targetstissue clearingwhole-body imagingtargeted covalent inhibitors 11 These authors contributed equally 12 Lead contact © 2025 The Authors. Published by Elsevier Inc.