ITK kinase domain in complex with compound 1 N-{1-[(1,1-dioxo-1-thian-2-yl)(phenyl)methyl]-1H- pyrazol-4-yl}-5,5-difluoro-5a-methyl-1H,4H,4aH,5H,5aH,6H-cyclopropa[f]indazole-3-carboxamide

Experimental Data Snapshot

  • Resolution: 2.10 Å
  • R-Value Free: 0.264 
  • R-Value Work: 0.203 
  • R-Value Observed: 0.206 

wwPDB Validation   3D Report Full Report

Ligand Structure Quality Assessment 

This is version 1.1 of the entry. See complete history


Tetrahydroindazoles as Interleukin-2 Inducible T-Cell Kinase Inhibitors. Part II. Second-Generation Analogues with Enhanced Potency, Selectivity, and Pharmacodynamic Modulation in Vivo.

Burch, J.D.Barrett, K.Chen, Y.DeVoss, J.Eigenbrot, C.Goldsmith, R.Ismaili, M.H.Lau, K.Lin, Z.Ortwine, D.F.Zarrin, A.A.McEwan, P.A.Barker, J.J.Ellebrandt, C.Kordt, D.Stein, D.B.Wang, X.Chen, Y.Hu, B.Xu, X.Yuen, P.W.Zhang, Y.Pei, Z.

(2015) J Med Chem 58: 3806-3816

  • DOI: https://doi.org/10.1021/jm501998m
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    The medicinal chemistry community has directed considerable efforts toward the discovery of selective inhibitors of interleukin-2 inducible T-cell kinase (ITK), given its role in T-cell signaling downstream of the T-cell receptor (TCR) and the implications of this target for inflammatory disorders such as asthma. We have previously disclosed a structure- and property-guided lead optimization effort which resulted in the discovery of a new series of tetrahydroindazole-containing selective ITK inhibitors. Herein we disclose further optimization of this series that resulted in further potency improvements, reduced off-target receptor binding liabilities, and reduced cytotoxicity. Specifically, we have identified a correlation between the basicity of solubilizing elements in the ITK inhibitors and off-target antiproliferative effects, which was exploited to reduce cytotoxicity while maintaining kinase selectivity. Optimized analogues were shown to reduce IL-2 and IL-13 production in vivo following oral or intraperitoneal dosing in mice.

  • Organizational Affiliation

    ∥Pharmaron Beijing Ltd. Co., No. 6 TaiHe Road BDA, 100176 Beijing, P. R. China.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Tyrosine-protein kinase ITK/TSK266Homo sapiensMutation(s): 3 
UniProt & NIH Common Fund Data Resources
Find proteins for Q08881 (Homo sapiens)
Explore Q08881 
Go to UniProtKB:  Q08881
PHAROS:  Q08881
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ08881
Sequence Annotations
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
Query on 3P6

Download Ideal Coordinates CCD File 
B [auth A](4aS,5aR)-N-{1-[(R)-[(2R)-1,1-dioxidotetrahydro-2H-thiopyran-2-yl](phenyl)methyl]-1H-pyrazol-4-yl}-5,5-difluoro-5a-methyl-1,4,4a,5,5a,6-hexahydrocyclopropa[f]indazole-3-carboxamide
C25 H27 F2 N5 O3 S
Binding Affinity Annotations 
IDSourceBinding Affinity
3P6 BindingDB:  4RFM Ki: 0.09 (nM) from 1 assay(s)
IC50: 4 (nM) from 1 assay(s)
Binding MOAD:  4RFM Ki: 0.09 (nM) from 1 assay(s)
Experimental Data & Validation

Experimental Data

  • Resolution: 2.10 Å
  • R-Value Free: 0.264 
  • R-Value Work: 0.203 
  • R-Value Observed: 0.206 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 40.006α = 90
b = 69.561β = 113.39
c = 47.347γ = 90
Software Package:
Software NamePurpose
CrystalCleardata collection
d*TREKdata reduction
d*TREKdata scaling

Structure Validation

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Ligand Structure Quality Assessment 

Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2015-04-29
    Type: Initial release
  • Version 1.1: 2015-08-26
    Changes: Database references