AZ7550 Mesylate is an active metabolite of AZD9291 and inhibits the activity of IGF1R with an IC 50 of 1.6 μM. In Vitro AZ7550 (Compound 28) appeares to offer a broadly similar potency and selectivity profile to the parent compound AZD9291. AZ7550 inhibits double mutant (DM) cell line H1975, activating mutant (AM) cell line PC9, and wild type (WT) cell line LoVo with IC 50 s of 45, 26, and 786 nM, respectively. AZ7550 inhibits DM antiproliferative cell line H1975, AM antiproliferative cell line PC9, and WT antiproliferative cell line Calu3 with GI 50 s of 19, 15, and 537 nM, respectively. MCE has not independently confirmed the accuracy of these methods. They are for reference only. Form:Solid IC50& Target:IC50: 1.6 μM (IGF1R), 88 nM (MLK1), 156 nM (ACK1), 195 nM (ErbB4), 228 nM (MNK2), 302 nM (FLT3), 420 nM (ALK ), 449 nM (FES), 840 nM (IRR), 843 nM (BRK), 977 nM (BLK), 995 nM (FAK), 1256 nM (Ins R), 1317 nM (TEC), 1784 nM (FLT4), 2288 nM (PYK2), 2443 nM (Txk), 5104 nM (BTK)