The in vitro data correlated with the expression of FGFRs in human CCA specimens by immunohistochemistry (FGFR1, 30% positive; and FGFR2, 65% positive) and the CCA cell lines assayed by Western blot analysis.
FGFR2 fusion events are present in up to 17% of intrahepatic CCAs and appear to predict sensitivity to FGFR inhibitors even after progression on chemotherapy.
Understanding the role of the FGFR2 pathway as a disease pathogenetic mechanism and the ability to develop targeted therapies and diagnostics surrounding this concept are critical elements toward developing novel targeted approaches in CCA.