Competing interests

HA reports personal fees from Ono, Bristol-Myers Squibb, Daiichi-Sankyo, Takeda, Chugai, Eisai and Delta-Fly Pharma. HI reports grants from Daiichi Sankyo Co., Ltd., Nippon Kayaku Co., Ltd., Chugai,,, Pharmaceutical Co., Ltd., Taiho Pharmaceutical Co., Ltd., Asahi Kasei Pharma Co., Ltd., Mochida Pharmaceutical Co., Ltd.; and reports personal fees from Taiho Pharmaceutical Co., Ltd., Chugai Pharmaceutical Co., Ltd., Yakult Honsha Co., Ltd., Astellas Pharma Co., Ltd., Eli Lilly and Company, Daiichi Sankyo Co., Ltd., AstraZeneca plc, Nippon Kayaku Co., Ltd., Ono, Pharmaceutical Co., Ltd. and Nippon Boehringer Ingelheim Co., Ltd. TM reports grants from AC Medical, A2 Healthcare, CAC Croit Corporation, Japan Tobacco Inc, Japan Media Corporation, Medidata Solutions, Inc, Ono Pharmaceutical, FMD K&L Japan, Intellim, Welby, Nipro Corporation, New Age Trading, NOBORI Ltd. And Medrio; and reports personal fees from AYUMI, Impute, Pfizer, Welby, EISAI, Merc and Takeda. KH reports grants from Pfizer. JE reports grants from Taiho Pharmaceutical Co., Ltd., Chugai Pharmaceutical Co., Ltd., Nippon, Boehringer Ingelheim Co., Ltd., Kyorin Holdings, Inc. and Nippon Kayaku Co., Ltd.; and reports personal fees from AstraZeneca plc, Chugai Pharmaceutical Co., Ltd., Bristol-Myers Squibb Co., Ltd., Takeda Pharmaceutical Co., Ltd., Novartis Pharma K.K. and Daiichi Sankyo Co., Ltd. NF reports personal fees from Eli Lilly Japan, AstraZeneca, Boehringer Ingelheim Japan, Chugai, Bristol Myers Squibb, Taiho, Pfizer Japan and Novartis. TY reports grants from AC MEDICAL INC., A2 Healthcare Corporation, EP Croit Co., Ltd., ClinChoice., Japan Tobacco Inc., Japan Media Corporation, Medidata Solutions, Inc., ONO PHARMACEUTICAL CO., LTD., Kyowa Kirin Co., Ltd., TSUMURA & CO., DAIICHI, SANKYO COMPANY, LIMITED., Otsuka Pharmaceutical Co., Ltd. Eisai Co., Ltd., ASAHI, INTECC CO., LTD., 3H Clinical Trial Inc., Medrio, Inc., NIPRO CORPORATION, Intellim Corporation, Welby Inc., 3H Medi Solution Inc., NIPRO CORPORATION, Baseconnect Inc., Nobori Ltd., Puravida Technologies LLC. and Hemp Kitchen Inc.; and reports personal fees from EPS Corporation, Japan Tobacco Inc., Medidata Solutions, Inc., ONO PHARMACEUTICAL CO., LTD., Kowa Company, Ltd., CHUGAI PHARMACEUTICAL CO. LTD., TSUMURA & CO., DAIICHI SANKYO COMPANY, LIMITED., Eisai Co., Ltd., ASAHI INTECC CO., LTD., ASAHI KASEI PHARMA CORPORATION, 3H Clinical Trial Inc. Intellim Corporation, Takeda, AstraZeneca, SONIRE Therapeutics Inc., SEIKAGAKU CORPORATION, Merck & Co., Inc. and NIPRO CORPORATION. TEN reports grants from Sumitomo Dainippon Pharma Co., Ono Pharmaceutical Co., Taiho Pharmaceutical Co., Takeda Pharmaceutical Co., Chugai Pharmaceutical Co., Sanofi K.K., Nippon Kayaku Co., MSD K.K. and Eli Lilly Japan K.K.; and reports personal fees from Thyas Co. Ltd., Rebirthel Co., Ltd., Japan Clinical Research Operations, Sumitomo Dainippon Pharma Co., Boehringer Ingelheim, Bristol-Myers Squibb, Ono Pharmaceutical Co., Taiho Pharmaceutical Co., Amgen, Takeda Pharmaceutical Co., Chugai Pharmaceutical Co., Sanofi K.K., Novartis Japan, Nippon Kayaku Co., MSD K.K., Eli Lilly Japan K.K., Bayer Yakuhin, Pfizer Japan Inc., Daiichi, Sankyo Co., Yakult Honsha Co., Nipro Co, Merck Serono Co., AstraZeneca, IQVIA and GlaxoSmithKline. All other authors declare no competing interests.

Ethics approval and consent to participate

This study was conducted in accordance with the Declaration of Helsinki and was approved by the institutional review board at each site. The study was registered with the University Hospital Medical Information Network, Clinical Trials Registry number UMIN000032269. All patients included in this study provided written, informed consent.

Consent for publication

All patients provided written, informed consent.