Irpagratinib (ABSK011) is an orally active inhibitor of fibroblast growth factor receptor ( FGFR ) tyrosine kinase, targeting to FGFR4 (IC50<10 nM). Irpagratinib inhibits the auto-phosphorylation of FGFR4 and blocks signal transduction from FGFR4 to downstream pathway activation. Irpagratinib exhibits high exposure in PK study in mouse, rat and dog, and also shows antineoplastic/anti-tumor activity in subcutaneous xenograft tumor models.