Remibrutinib, is a potent and orally active bruton tyrosine kinase (BTK) inhibitor with an IC50 value of 1 nM. Remibrutinib inhibits BTK activity with an IC50 value of 0.023 μM in blood. Remibrutinib has the potential for Chronic urticaria (CU) treatment[2].IC50 & Target: IC50: 1 nM (BTK)In Vitro: In a biochemical enzyme assay,Remibrutinib (example 6) inhibits Btk enzymatic activity with an IC50 value of 1 nM.In vitro B cell activation assay, Remibrutinib inhibits Btk enzymatic activity in blood with an IC50 value of 0.023 μM, the whole blood is collected from the abdominal aorta of anaesthetized adult male Lewis rats.