Footnotes

• Handling editor Tore K Kvien.

• Contributors KO contributed to the study design, overall review, writing of the manuscript, and the other authors were involved in performance of the study coordination. KY, YK, KK and SM enrolled and managed patients in the clinic. All authors read and approved the final manuscript.

• Competing interests KO and SM have received speaking fees from Abbvie, Chugai, Tanabe-Mitsubishi, Astellas, Eisai, Janssen, Pfizer, UCB and Ono.

• Patient consent Obtained.

• Ethics approval Matsuyama Red Cross Hospital.

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