Alectinib (CH5424802)S2762

The dissociation constant (KD) value of CH5424802 for ALK in an ATP-competitive manner is 2.4 nM. CH5424802 has substantial inhibitory potency against both native ALK and L1196M with K_i of 0.83 nM and 1.56 nM, respectively. CH5424802 prevents autophosphorylation of ALK in NCI-H2228 NSCLC cells expressing EML4-ALK. CH5424802 also suppresses the phosphorylation of STAT3 and AKT, but not of ERK1/2. CH5424802 completely inhibits the phosphorylation of STAT3 at Tyr705. CH5424802 is preferentially efficacious against NCI-H2228 cells expressing EML4-ALK, but not ALK fusion-negative NSCLC cell lines, including HCC827 cells (EGFR exon 19 deletion), A549 cells (KRAS mutant), or NCI-H522 cells (EGFR wild-type, KRAS wild-type, and ALK wild-type) in monolayer culture. CH5424802 elicits an apoptotic marker—caspase-3/7-like activation—in NCI-H2228 spheroid cells. CH5424802 blocks the growth of two lymphoma lines, KARPAS-299 and SR, with NPM-ALK fusion protein but does not influence the growth of an HDLM-2 lymphoma line without ALK fusion. ^[1] CH5424802 displays high target selectivity and the stronger anti-proliferative activity against KARPAS-299. CH5424802 inhibits KAPRAS-299 with an IC50 of 3 nM, and KDR with IC50 of 1.4 μM. The metabolic stability of CH5424802 is very high.^[2]