Discovery, Optimization, and Biological Evaluation of Arylpyridones as Cbl-b Inhibitors.
Mfuh, A.M., Boerth, J.A., Bommakanti, G., Chan, C., Chinn, A.J., Code, E., Fricke, P.J., Giblin, K.A., Gohlke, A., Hansel, C., Hariparsad, N., Hughes, S.J., Jin, M., Kantae, V., Kavanagh, S.L., Lamb, M.L., Lane, J., Moore, R., Puri, T., Quinn, T.R., Reddy, I., Robb, G.R., Robbins, K.J., Gancedo Rodrigo, M., Schimpl, M., Singh, B., Singh, M., Tang, H., Thomson, C., Walsh, J.J., Ware, J., Watson, I.D.G., Ye, M.W., Wrigley, G.L., Zhang, A.X., Zhang, Y., Grimster, N.P.(2024) J Med Chem 67: 1500-1512
- PubMed: 38227216 
- DOI: https://doi.org/10.1021/acs.jmedchem.3c02083
- Primary Citation of Related Structures:  
8QTG, 8QTH, 8QTJ, 8QTK - PubMed Abstract: 
Casitas B-lymphoma proto-oncogene-b (Cbl-b), a member of the Cbl family of RING finger E3 ubiquitin ligases, has been demonstrated to play a central role in regulating effector T-cell function. Multiple studies using gene-targeting approaches have provided direct evidence that Cbl-b negatively regulates T, B, and NK cell activation via a ubiquitin-mediated protein modulation. Thus, inhibition of Cbl-b ligase activity can lead to immune activation and has therapeutic potential in immuno-oncology. Herein, we describe the discovery and optimization of an arylpyridone series as Cbl-b inhibitors by structure-based drug discovery to afford compound 31 . This compound binds to Cbl-b with an IC 50 value of 30 nM and induces IL-2 production in T-cells with an EC 50 value of 230 nM. Compound 31 also shows robust intracellular target engagement demonstrated through inhibition of Cbl-b autoubiquitination, inhibition of ubiquitin transfer to ZAP70, and the cellular modulation of phosphorylation of a downstream signal within the TCR axis.
Organizational Affiliation: 
Oncology R&D, AstraZeneca, Waltham, Massachusetts 02451, United States.