Specific, first-in-class inhibitor of histone kinase Haspin, which blocks H3T3 phosphorylation in association with a characteristic spindle and centrosome phenotype (IC50 values are 500 nM, 473 nM and 752 nM for apoptosis induction in HCT-116, HeLa and MDA-MB-231 cells, respectively). CHR 6494 causes arrest in G2/M, induces apoptosis and possesses ex vivo anti-angiogenesis features and antitumoral properties in a nude mice xenograft model. Haspin function is critical in mitosis, favouring chromosome cohesion, metaphase alignment and progression through the cell cycle.