Exploratory subgroup analysis of patients with prior trastuzumab use in the ATTRACTION-2 trial: a randomized phase III clinical trial investigating the efficacy and safety of nivolumab in patients with advanced gastric/gastroesophageal junction cancer.

"Conflicts of interest Taroh Satoh received donations for his department from Ono Pharmaceutical, Yakult Honsha, and Chugai Pharmaceutical and received research grants and honoraria from Ono Pharmaceutical, Yakult Honsha, Chugai Pharmaceutical, Eli Lilly, Bristol Myers Squibb, Merck Serono, Takeda Pharmaceutical, Taiho Pharmaceutical, and MSD. Yoon-Koo Kang is a consultant for Ono Pharmaceutical, Bristol Myers Squibb, Daehwa Pharmaceutical, LSK Biopharma, AstraZeneca, Merck Serono, and Novartis. Min-Hee Ryu received honorarium and served on the advisory boards for Ono Pharmaceutical, Bristol Myers Squibb, MSD, Eli Lilly, Taiho Pharmaceutical, Novartis, and Daehwa Pharmaceutical. Ken Kato received research grants from Ono Pharmaceutical, MSD, Shionogi, Merck Serono, and Beigene. Hyun Cheol Chung received research grants from Ono Pharmaceutical, Eli Lilly, GSK, MSD, Merck Serono, and Taiho Pharmaceutical, honoraria from Merck Serono, Eli Lilly, and Foundation Medicine/Roche, and consultation fees from Taiho Pharmaceutical, Celltrion, MSD, Eli Lilly, Quintiles, BMS, and Merck Serono. Jen-Shi Chen received research grants and consulting fees from Ono Pharmaceutical. Kei Muro received research grants from Ono Pharmaceutical, MSD, Daiichi Sankyo, Kyowa Hakko Kirin, Shionogi Pharmaceutical, and Gilead Sciences and personal fees from Chugai Pharmaceutical, Taiho Pharmaceutical, Takeda Pharmaceutical, Merck Serono, Eli Lilly, and Yakult Honsha. Kun-Huei Yeh received personal fees from Ono Pharmaceutical, Boehringer Ingelheim, Takeda Pharmaceutical, Bristol Myers Squibb, MSD, Eli Lilly, and Amgen. Takaki Yoshikawa received research grants from Ono Pharmaceutical and Bristol Myers Squibb, Chugai Pharmaceutical, and Taiho Pharmaceutical, honoraria from Chugai Pharmaceutical, Taiho Pharmaceutical, Bristol Myers Squibb, Ono Pharmaceutical, Eli Lilly, Yakult Honsha, Nippon Kayaku, Johnson and Johnson, Covidien, Olympus, Daiichi Sankyo, MSD, and Terumo. Takao Tamura received research grants from Ono Pharmaceutical, Bristol Myers Squibb, MSD, Merck Serono, Daiichi Sankyo, Takeda Pharmaceutical, and Chugai Pharmaceutical and personal fees from Daiichi Sankyo and Takeda Pharmaceutical. Do-Youn Oh received research grants from Astra Zeneca. Yee Chao, Won Ki Kang, Sang Cheul Oh, Li-Yuan Bai, Yasuo Hamamoto, Jong Gwang Kim, Keisho Chin, Keiko Minashi, Jae Yong Cho, Keun-Wook Lee, and Masahiro Tsuda received research grants from Ono Pharmaceutical. Mitsunobu Tanimoto is an employee of Ono Pharmaceutical. Li-Tzong Chen received research grants from Ono Pharmaceutical, Bristol Myers Squibb, Ministry of Science and Technology, Taiwan, Ministry of Health and Welfare, Taiwan, Novartis, Pfizer, TTY Biopharm, OBI Pharma, Polaris Pharma, Syncore Biotechnology, and Celgene, personal fees from Ono Pharmaceutical, Bristol Myers Squibb, Novartis, Eli Lilly, TTY Biopharm, PharmaEngine, Shire, MSD, Five Prime Therapeutics, AstraZeneca, and Ipsen, and non-financial support from Novartis, TTY Biopharm, PharmaEngine, Syncore, and Celgene. Narikazu Boku received research grants from Ono Pharmaceutical and Taiho Pharmaceutical and personal fees from Ono Pharmaceutical, Chugai Pharmaceutical, Merck Serono, AstraZeneca, and Taiho Pharmaceutical."

"Funding This study was funded by Ono Pharmaceutical Co., Ltd., Osaka, Japan, and Bristol-Myers Squibb, Inc., Princeton, NJ."