Conflict of interest: H. Fujimoto reports grants from Chugai, Pfizer, ONO, TAIHO, Boehringer Ingelheim and Eli Lilly, outside the submitted work. T. Yasuma reports grants from Shionogi, outside the submitted work. C.N. D'Alessandro-Gabazza reports grants from Shionogi Pharmaceutical Inc., Astellas Pharmaceuticals Inc. and Asahi Kassei, outside the submitted work. E.C. Gabazza reports grants from Shionogi Pharmaceutical Inc., Astellas Pharmaceuticals Inc. and Asahi Kassei, outside the submitted work. O. Hataji reports grants from Janssen Pharmaceutical, Chugai Pharmaceutical, Eli Lilly, Fukuda Denshi and Kyorin Pharmaceutical, grants and personal fees from AstraZeneca, Boehringer Ingelheim, GlaxoSmithKline, Merk Sharp & Dohme (MSD), Novartis, Ono Pharmaceutical, Sanofi Pharmaceutical and Takeda Pharmaceutical, personal fees from Mitsubishi Tanabe Pharma, Nippon Kayaku, Nippon Chemiphar and Taiho Pharmaceutical, outside the submitted work. T. Kobayashi reports grants and personal fees from Chugai, Pfizer, ONO, Boehringer Ingelheim and Eli Lilly, grants from TAIHO, outside the submitted work.