Conflict of interest

Koji Kato reports honoraria from Bristol Myers Squibb, Celgene, Dainippon-Sumitomo, Janssen, Kyowa Kirin, MSD, Mundi, and Ono; consulting or advisory roles with AbbVie, AstraZeneca, Celgene, Chugai Pharmaceutical, Daiichi Sankyo, Eisai, Janssen, and Novartis; and research funding from AbbVie, Bristol Myers Squibb, Celgene, Chugai, Daiichi Sankyo, Eisai, Janssen, Kyowa Kirin, MSD, Novartis, and Ono. Sosuke Nakamura reports employment at MSD K.K., Tokyo, Japan. Akira Wakana reports employment at MSD K.K., Tokyo, Japan, and stock ownership in Merck & Co., Inc., Rahway, NJ, USA. Yasuhiro Koh reports employment at MSD K.K., Tokyo, Japan, and stock ownership in Merck & Co., Inc., Rahway, NJ, USA. Koji Izutsu reports research grants from AstraZeneca, AbbVie, Incyte, Bristol Myers Squibb, Novartis, Janssen, Chugai, BeiGene, and Genmab. This study was designed under the responsibility of, and was supported by, Merck Sharp & Dohme LLC, a subsidiary of Merck & Co., Inc., Rahway, NJ, USA, and MSD.K.K., Tokyo, Japan, in conjunction with the steering committee. Merck Sharp & Dohme LLC, a subsidiary of Merck & Co., Inc., Rahway, NJ, USA, and MSD.K.K., Tokyo, collected and analyzed the data and contributed to the interpretation of the study. All authors had full access to all of the data in the study and had final responsibility for the decision to submit for publication.

Ethical approval

Ethical approval of the research protocol by an Institutional Review Board: The study protocol and all amendments were approved by the appropriate institutional review boards and ethics review committees at each center. The study was conducted in accordance with the protocol, Good Clinical Practice guidelines, and the Declaration of Helsinki.

Informed consent

All patients provided written informed consent before enrollment.