Footnotes

• Contributors All the authors evaluated the study results, interpreted the data and suggested additional analyses. All authors contributed to the development and critical review of manuscript and approved the final version.

• Funding This study was supported by Chugai Pharmaceutical Co, Ltd.

• Competing interests MH is an employee of Chugai Pharmaceutical Co, Ltd. TT has received consulting fees, speaking fees, honoraria and/or research grant support from Abbott Japan Co; Abbvie GK; Asahi Kasei Pharma Corp; Astellas Pharma Inc; Astra-Zeneca KK; Bristol-Myers KK; Chugai Pharmaceutical Co, Ltd; Daiichi-Sankyo Co; Eisai Co; Eli-Lilly Japan KK; Janssen Pharmaceutical KK; Mitsubishi Tanabe Pharma Co; Novartis Pharma KK; Pfizer Japan Inc; Sanofi-aventis KK; Santen Pharmaceutical Co, Ltd; Taisho Toyama Pharmaceutical Co, Ltd; Takeda Pharmaceutical Co, Ltd; and Teijin Pharma Ltd.

• Patient consent Obtained.

• Ethics approval The ethics committee at Keio University School of Medicine.

• Provenance and peer review Not commissioned; externally peer reviewed.