FGFR2 Extracellular Domain In-Frame Deletions Are Therapeutically Targetable Genomic Alterations That Function as Oncogenic Drivers in Cholangiocarcinoma.

Abstract

We conducted next-generation DNA sequencing on 335 biliary tract cancers and characterized the genomic landscape by anatomic site within the biliary tree. In addition to frequent FGFR2 fusions among patients with intrahepatic cholangiocarcinoma (IHCC), we identified FGFR2 extracellular domain in-frame deletions (EID) in 5 of 178 (2.8%) patients with IHCC, including two patients with FGFR2 p.H167_N173del. Expression of this FGFR2 EID in NIH3T3 cells resulted in constitutive FGFR2 activation, oncogenic transformation, and sensitivity to FGFR inhibitors. Three patients with FGFR2 EIDs were treated with Debio 1347, an oral FGFR1/2/3 inhibitor, and all showed partial responses. One patient developed an acquired L618F FGFR2 kinase domain mutation at disease progression and experienced a further partial response for 17 months to an irreversible FGFR2 inhibitor, futibatinib. Together, these findings reveal FGFR2 EIDs as an alternative mechanism of FGFR2 activation in IHCC that predicts sensitivity to FGFR inhibitors in the clinic. SIGNIFICANCE: FGFR2 EIDs are transforming genomic alterations that occur predominantly in patients with IHCC. These FGFR2 EIDs are sensitive to FGFR inhibition in vitro, and patients with these alterations benefited from treatment with FGFR inhibitors in the clinic.This article is highlighted in the In This Issue feature, p. 2355.

• Authors: James M Cleary, Srivatsan Raghavan, Qibiao Wu, Yvonne Y Li, Liam F Spurr, Hersh V Gupta, Douglas A Rubinson, Isobel J Fetter, Jason L Hornick, Jonathan A Nowak, Giulia Siravegna, Lipika Goyal, Lei Shi, Lauren K Brais, Maureen Loftus, Atul B Shinagare, Thomas A Abrams, Thomas E Clancy, Jiping Wang, Anuj K Patel, Franck Brichory, Anne Vaslin Chessex, Ryan J Sullivan, Rachel B Keller, Sarah Denning, Emma R Hill, Geoffrey I Shapiro, Anna Pokorska-Bocci, Claudio Zanna, Kimmie Ng, Deborah Schrag, Pasi A Jänne, William C Hahn, Andrew D Cherniack, Ryan B Corcoran, Matthew Meyerson, Antoine Daina, Vincent Zoete, Nabeel Bardeesy, Brian M Wolpin
• Journal: Cancer discovery (Cancer Discov) Vol. 11 Issue 10 Pg. 2488-2505 (10 2021) ISSN: 2159-8290 [Electronic] United States
• PMID: 33926920 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)
• Copyright: ©2021 American Association for Cancer Research.

Chemical References

• Protein Kinase Inhibitors
• FGFR2 protein, human
• Receptor, Fibroblast Growth Factor, Type 2

Topics

• Adolescent
• Adult
• Aged
• Aged, 80 and over
• Bile Duct Neoplasms (drug therapy, genetics, pathology)
• Cholangiocarcinoma (drug therapy, genetics, pathology)
• Female
• Humans
• Male
• Middle Aged
• Molecular Targeted Therapy
• Protein Kinase Inhibitors (therapeutic use)
• Receptor, Fibroblast Growth Factor, Type 2 (antagonists & inhibitors, genetics)
• Young Adult