Discovery and clinical validation of RLY-4008, the first highly selective FGFR2 inhibitor with activity across FGFR2 alterations and resistance mutations

Experimental Data Snapshot

  • Resolution: 3.79 Å
  • R-Value Free: 0.311 
  • R-Value Work: 0.307 
  • R-Value Observed: 0.307 

wwPDB Validation   3D Report Full Report

Ligand Structure Quality Assessment 

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RLY-4008, the First Highly Selective FGFR2 Inhibitor with Activity across FGFR2 Alterations and Resistance Mutations.

Subbiah, V.Sahai, V.Maglic, D.Bruderek, K.Toure, B.B.Zhao, S.Valverde, R.O'Hearn, P.J.Moustakas, D.T.Schonherr, H.Gerami-Moayed, N.Taylor, A.M.Hudson, B.M.Houde, D.J.Pal, D.Foster, L.Gunaydin, H.Ayaz, P.Sharon, D.A.Goyal, L.Schram, A.M.Kamath, S.Sherwin, C.A.Schmidt-Kittler, O.Jen, K.Y.Ricard, F.Wolf, B.B.Shaw, D.E.Bergstrom, D.A.Watters, J.Casaletto, J.B.

(2023) Cancer Discov 13: 2012-2031

  • DOI: https://doi.org/10.1158/2159-8290.CD-23-0475
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    Oncogenic activation of fibroblast growth factor receptor 2 (FGFR2) drives multiple cancers and represents a broad therapeutic opportunity, yet selective targeting of FGFR2 has not been achieved. Although the clinical efficacy of pan-FGFR inhibitors (pan-FGFRi) validates FGFR2 driver status in FGFR2 fusion-positive intrahepatic cholangiocarcinoma, their benefit is limited by incomplete target coverage due to FGFR1- and FGFR4-mediated toxicities (hyperphosphatemia and diarrhea, respectively) and the emergence of FGFR2 resistance mutations. RLY-4008 is a highly selective, irreversible FGFR2 inhibitor designed to overcome these limitations. In vitro, RLY-4008 demonstrates >250- and >5,000-fold selectivity over FGFR1 and FGFR4, respectively, and targets primary alterations and resistance mutations. In vivo, RLY-4008 induces regression in multiple xenograft models-including models with FGFR2 resistance mutations that drive clinical progression on current pan-FGFRi-while sparing FGFR1 and FGFR4. In early clinical testing, RLY-4008 induced responses without clinically significant off-isoform FGFR toxicities, confirming the broad therapeutic potential of selective FGFR2 targeting.

  • Organizational Affiliation

    The University of Texas MD Anderson Cancer Center, Houston, Texas.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Fibroblast growth factor receptor 2
A, B
317Homo sapiensMutation(s): 0 
UniProt & NIH Common Fund Data Resources
Find proteins for P21802 (Homo sapiens)
Explore P21802 
Go to UniProtKB:  P21802
PHAROS:  P21802
GTEx:  ENSG00000066468 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP21802
Sequence Annotations
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
WCJ (Subject of Investigation/LOI)
Query on WCJ

Download Ideal Coordinates CCD File 
C [auth A],
D [auth B]
C28 H26 F N7 O2
Experimental Data & Validation

Experimental Data

  • Resolution: 3.79 Å
  • R-Value Free: 0.311 
  • R-Value Work: 0.307 
  • R-Value Observed: 0.307 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 62.51α = 90
b = 91.34β = 90
c = 129.62γ = 90
Software Package:
Software NamePurpose
autoPROCdata reduction
autoPROCdata scaling

Structure Validation

View Full Validation Report

Ligand Structure Quality Assessment 

Entry History & Funding Information

Deposition Data

Funding OrganizationLocationGrant Number
Other private--

Revision History  (Full details and data files)

  • Version 1.0: 2023-06-07
    Type: Initial release
  • Version 1.1: 2023-06-14
    Changes: Database references
  • Version 1.2: 2023-09-13
    Changes: Data collection, Database references
  • Version 2.0: 2023-09-20
    Changes: Atomic model, Data collection, Derived calculations, Non-polymer description, Structure summary
  • Version 3.0: 2023-10-18
    Type: Coordinate replacement
    Reason: Ligand geometry
    Changes: Advisory, Atomic model, Data collection, Derived calculations, Refinement description
  • Version 3.1: 2023-10-25
    Changes: Refinement description