Patent 11185594 was granted and assigned to Daiichi Sankyo on November, 2021 by the United States Patent and Trademark Office.
As an antitumor drug which is excellent in terms of antitumor effect and safety and has an excellent therapeutic effect, there is provided an antibody-drug conjugate in which an antitumor compound represented by the following formula is conjugated to an anti-HER2 antibody via a linker having a structure represented by the formula: L1-L2-LP-NH—(CH2)n1-La-Lb-Lc or -L1-L2-LP- wherein the anti-HER2 antibody is connected to the terminal L1, and the antitumor compound is connected to the terminal Lc or LP with the nitrogen atom of the amino group at position 1 as the connecting position.