Discovery and development of trastuzumab deruxtecan and safety management for patients with HER2-positive gastric cancer.

"Declarations Conflict of interestK Shitara reports paid consulting or advisory roles for Astellas, Eli Lilly, Bristol-Myers Squibb, Takeda, Pfizer, Ono, MSD, Taiho, Novartis, AbbVie, and GSK; honoraria from Novartis, AbbVie, and Yakult; and research funding from Astellas, Eli Lilly, Ono, Sumitomo Dainippon, Daiichi Sankyo, Taiho, Chugai, MSD, and Medi Science, outside the submitted work. E Baba reports grants and personal fees from Taiho, Chugai, Astellas, Merck Biopharma, Daiichi Sankyo, Ono, Kyowa-Kirin, Eisai, Eli Lilly, MSD, Sanofi, Yakult, and Takeda. K Fujitani reports personal fees from Bristol-Myers Squibb, Eli Lilly, Ono, Taiho, and Yakult. E Oki reports personal fees from Taiho, Takeda, Chugai, Eli Lilly, Ono, and Bayer. S Fujii has nothing to declare. K Yamaguchi reports grants and personal fees from Taiho, Chugai, Daiichi Sankyo, Ono, and Eli Lilly; personal fees from Takeda, Merck Serono, Bayer, and Bristol-Myers Squibb; and grants from MSD, Gilliad, Sumitomo Dainippon, Boehringer Ingelheim, and Sanofi. Conflict of interest K Shitara reports paid consulting or advisory roles for Astellas, Eli Lilly, Bristol-Myers Squibb, Takeda, Pfizer, Ono, MSD, Taiho, Novartis, AbbVie, and GSK; honoraria from Novartis, AbbVie, and Yakult; and research funding from Astellas, Eli Lilly, Ono, Sumitomo Dainippon, Daiichi Sankyo, Taiho, Chugai, MSD, and Medi Science, outside the submitted work. E Baba reports grants and personal fees from Taiho, Chugai, Astellas, Merck Biopharma, Daiichi Sankyo, Ono, Kyowa-Kirin, Eisai, Eli Lilly, MSD, Sanofi, Yakult, and Takeda. K Fujitani reports personal fees from Bristol-Myers Squibb, Eli Lilly, Ono, Taiho, and Yakult. E Oki reports personal fees from Taiho, Takeda, Chugai, Eli Lilly, Ono, and Bayer. S Fujii has nothing to declare. K Yamaguchi reports grants and personal fees from Taiho, Chugai, Daiichi Sankyo, Ono, and Eli Lilly; personal fees from Takeda, Merck Serono, Bayer, and Bristol-Myers Squibb; and grants from MSD, Gilliad, Sumitomo Dainippon, Boehringer Ingelheim, and Sanofi."

"Funding This work was funded by Daiichi Sankyo Co., Ltd."