Acalabrutinib is a selective inhibitor of Bruton's tyrosine kinase (BTK). BTK is a signaling molecule of B-cell antigen receptors and cytokine receptors. In B-cells, BTK signaling promotes B-cell survival and proliferation and is required for cell adhesion, migration, and chemotaxis. Acalabrutinib and its active metabolite ACP-5862 form a covalent bond with a cysteine residue in the BTK active site, resulting in irreversible inactivation of BTK with minimal off-target interactions.
