1. Academic Validation
  2. Development of Selective Covalent Janus Kinase 3 Inhibitors

Development of Selective Covalent Janus Kinase 3 Inhibitors

  • J Med Chem. 2015 Aug 27;58(16):6589-606. doi: 10.1021/acs.jmedchem.5b00710.
Li Tan 1 Koshi Akahane Randall McNally 1 Kathleen M S E Reyskens 2 Scott B Ficarro 1 Suhu Liu Grit S Herter-Sprie Shohei Koyama Michael J Pattison 2 Katherine Labella Liv Johannessen 1 Esra A Akbay Kwok-Kin Wong David A Frank Jarrod A Marto 1 Thomas A Look J Simon C Arthur 2 Michael J Eck 1 Nathanael S Gray 1
Affiliations

Affiliations

  • 1 Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School , Boston, Massachusetts 02115, United States.
  • 2 Division of Cell Signaling and Immunology, College of Life Sciences, University of Dundee , Dundee DD1 5EH. U.K.
Abstract

The Janus kinases (JAKs) and their downstream effectors, signal transducer and activator of transcription proteins (STATs), form a critical immune cell signaling circuit, which is of fundamental importance in innate immunity, inflammation, and hematopoiesis, and dysregulation is frequently observed in immune disease and Cancer. The high degree of structural conservation of the JAK ATP binding pockets has posed a considerable challenge to medicinal chemists seeking to develop highly selective inhibitors as pharmacological probes and as clinical drugs. Here we report the discovery and optimization of 2,4-substituted pyrimidines as covalent JAK3 inhibitors that exploit a unique cysteine (Cys909) residue in JAK3. Investigation of structure-activity relationship (SAR) utilizing biochemical and transformed Ba/F3 cellular assays resulted in identification of potent and selective inhibitors such as compounds 9 and 45. A 2.9 Å cocrystal structure of JAK3 in complex with 9 confirms the covalent interaction. Compound 9 exhibited decent pharmacokinetic properties and is suitable for use in vivo. These inhibitors provide a set of useful tools to pharmacologically interrogate JAK3-dependent biology.

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