title: Covalent inhibitors of interleukin-2 inducible T cell kinase (itk) with nanomolar potency in a whole-blood assay.
abstract: We wish to report a strategy that targets interleukin-2 inducible T cell kinase (Itk) with covalent inhibitors. Thus far, covalent inhibition of Itk has not been disclosed in the literature. Structure-based drug design was utilized to achieve low nanomolar potency of the disclosed series even at high ATP concentrations. Kinetic measurements confirmed an irreversible binding mode with off-rate half-lives exceeding 24 h and moderate on-rates. The analogues are highly potent in a cellular IP1 assay as well as in a human whole-blood (hWB) assay. Despite a half-life of approximately 2 h in resting primary T cells, the covalent inhibition of Itk resulted in functional silencing of the TCR pathway for more than 24 h. This prolonged effect indicates that covalent inhibition is a viable strategy to target the inactivation of Itk.
authors.affiliation: BioTherapeutics Chemistry, Pfizer Worldwide Medicinal Chemistry, 200 Cambridgepark Drive, Cambridge, Massachusetts 02140, USA. christoph.zapf@pfizer.com
authors.forename: Christoph W
authors.initials: CW
authors.lastname: Zapf
authors.forename: Brian S
authors.initials: BS
authors.lastname: Gerstenberger
authors.forename: Li
authors.initials: L
authors.lastname: Xing
authors.forename: David C
authors.initials: DC
authors.lastname: Limburg
authors.forename: David R
authors.initials: DR
authors.lastname: Anderson
authors.forename: Nicole
authors.initials: N
authors.lastname: Caspers
authors.forename: Seungil
authors.initials: S
authors.lastname: Han
authors.forename: Ann
authors.initials: A
authors.lastname: Aulabaugh
authors.forename: Ravi
authors.initials: R
authors.lastname: Kurumbail
authors.forename: Subarna
authors.initials: S
authors.lastname: Shakya
authors.forename: Xin
authors.initials: X
authors.lastname: Li
authors.forename: Vikki
authors.initials: V
authors.lastname: Spaulding
authors.forename: Robert M
authors.initials: RM
authors.lastname: Czerwinski
authors.forename: Nilufer
authors.initials: N
authors.lastname: Seth
authors.forename: Quintus G
authors.initials: QG
authors.lastname: Medley
mesh_terms: D015195:Drug Design; D006207:Half-Life; D006801:Humans; D007376:Interleukin-2 / Q000494:pharmacology*; D007700:Kinetics; D008958:Models, Molecular; D015394:Molecular Structure; D047428:Protein Kinase Inhibitors / Q000097:blood* / Q000138:chemical synthesis / Q000494:pharmacology*; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D011948:Receptors, Antigen, T-Cell / Q000037:antagonists & inhibitors*; D013329:Structure-Activity Relationship; D013601:T-Lymphocytes / Q000201:enzymology*
chemical_list: D007376:Interleukin-2; D047428:Protein Kinase Inhibitors; D011948:Receptors, Antigen, T-Cell; D011505:Protein-Tyrosine Kinases; C080813:emt protein-tyrosine kinase