Remibrutinib is a potent, highly selective covalent inhibitor of bruton tyrosine kinase (BTK) with IC50 of 1.3 nM, 2.5 nM and 18 nM for BTK, FcγR-induced IL8 and anti-IgM/IL4-induced CD69, respectively. Remibrutinib (LOU064) exhibits an exquisite kinase selectivity due to binding to an inactive conformation of BTK and has the potential for the treatment of autoimmune diseases.