AZ 5104 is an active, demethylated metabolite of AZD 9291 (Item No. 16237), an irreversible inhibitor of EGFR-sensitizing and T790M resistance mutations (IC50s = 15-17 nM) that spares the wild-type form of the receptor (IC50 = 480 nM). AZ 5104 displays a similar overall activity profile as the parent compound.