L718 and/or L792 mutant treatment-resistant EGFR inhibitor
The present invention provides an antitumor agent for treating a malignant tumor patient expressing EGFR having at least one mutation selected from the group consisting of L718X mutation in exon 18 and L792X mutation in exon 20, wherein X represents an arbitrary amino-acid residue, the antitumor agent comprising(S)—N-(4-amino-6-methyl-5-(quinolin-3-yl)-8.9-dihydropyrimido[5.4-b]indolizin-8-yl)acrylamide (Compound (A)) or a salt thereof.
1 . A method for treating a patient having lung cancer, comprising administering(S)—N-(4-amino-6-methyl-5-(quinolin-3-yl)-8,9-dihydropyrimido[5,4-b]indolizin-8-yl) acrylamide, as Compound (A), or a salt thereof to the patient expressing EGFR having at least one mutation selected from the group consisting of L718X mutation in exon 18 and L792X mutation in exon 20.
2 . The method according to claim 1 , wherein the EGFR further has at least one mutation selected from the group consisting of exon 19 deletion mutations L858R, L861Q, G719X, E709X, and an exon 20 insertion mutation.
3 . The method according to claim 2 , wherein the EGFR further has a T790M mutation.
4 . The method according to claim 1 , wherein the L718X mutation is a L718Q mutation.
5 . The method according to claim 1 , wherein the L792X mutation is L792H, L792F, or L792Y.
6 . The method according to claim 1 , wherein the(S)—N-(4-amino-6-methyl-5-(quinolin-3-yl)-8,9-dihydropyrimido[5,4-b]indolizin-8-yl) acrylamide or a salt thereof is administered to the patient in a form of a pharmaceutical composition further comprising a pharmaceutically acceptable carrier.