Acalabrutinib (ACP-196) 是选择性的第二代BTK抑制剂，抑制B细胞表面原抗体信号通路的激活，IC50为3 nM。它具有很好的靶标特异性，对BTK的选择性比对其他TEC激酶家族成员如ITK、TXK、BMK和TEC的选择性高323-, 94-, 19-, 9-倍。对EGFR没有活性。 Information Acalabrutinib (ACP-196) Acalabrutinib (ACP-196) is a selective second-generation Bruton's tyrosine kinase (BTK) inhibitor with an IC50 of 3 nM, which prevents the activation of the B-cell antigen receptor (BCR) signaling pathway. ACP-196 has improved target specificity over ibrutinib with 323-, 94-, 19- and 9-fold selectivity over the other TEC kinase family members (ITK, TXK, BMX, and TEC, respectively) and no activity against EGFR. Targets BTK (in a human whole-blood CD69 B cell activation assay) 3nM In vitro In the in vitro signaling assay on primary human CLL cells, acalabrutinib inhibits tyrosine phosphorylation of downstream targets of ERK, IKB, and AKT. Acalabrutinib demonstrates higher selectivity for BTK with IC50 determinations on nine kinases with a cysteine residue in the same position as BTK. Importantly, unlike ibrutinib, acalabrutinib does not inhibit EGFR, ITK, or TEC. acalabrutinib has no effect on EGFR phosphorylation on tyrosine residues Y1068 and Y1173. Compared with ibrutinib, acalabrutinib has much higher IC50(>1000 nM) or virtually no inhibition on kinase activities of ITK, EGFR, ERBB2, ERBB4, JAK3, BLK, FGR, FYN, HCK, LCK, LYN, SRC, and YES1. In vivo oral administration of ACP-196 in mice results in dose-dependent inhibition of anti-IgM-induced CD86 expression in CD19+ splenocytes with an ED50 of 0.34 mg/kg compared to 0.91 mg/kg for ibrutinib. A similar model is used to compare the duration of Btk inhibition after a single oral dose of 25 mg/kg. ACP-196 inhibits CD86 expression >90% at 3h postdose. Cell Research(from reference) Cell lines：primary human CLL cells,T cells, NK cells, and epithelial cells