Received: 17 September 2020
Accepted: 21 January 2021
First Online: 4 February 2021
Ethics approval and consent to participate
: The study was conducted in accordance with the guidelines of the Declaration of Helsinki and approved by the Hidaka Hospital Medical Ethics Committee (approval number: Heisei Hidaka Clinic 29). Consent to participate is not applicable.
: Not applicable.
: NN has received consulting fees from Kyowa Kirin Co., Ltd (KK) and Sanwa Kagaku Kenkyusho Co., Ltd and lecture fees from KK, Nobelpharma Co., Ltd, Torii Pharmaceutical Co., Ltd, Ono Pharmaceutical Co., Ltd (Ono), and Kissei Pharmaceutical Co., Ltd. T Ogawa has received grants (research support) from Takeda Pharmaceutical Co., Ltd, Chugai Pharmaceutical Co., Ltd, Ono, Mitsubishi Tanabe Pharma Co., Ltd, and Daiichi Sankyo Co., Ltd. The other authors declare that they have no competing interests.