[Questionnaire Survey on Adoption and Prescription of Biosimilars (Antibody and Its-related Products) by Medical Doctors in Japan].

Biosimilars are less expensive than their originators, and Japanese government policies call for their development and promotion. However, the adoption and prescription of some biosimilars, especially antibody/its-related ones, have been delayed for use in Japan, possibly due to concerns on the differences in quality attributes such as glycan structures between the originators and their biosimilars, and that clinical efficacy/safety studies are conducted for usually one disease and its results extrapolated to other indications. We conducted a questionnaire survey among physicians in four disease areas (hematology, medical oncology, rheumatoid arthritis, and inflammatory bowel disease), where biosimilars of antibody/its-related drugs have been approved, regarding their thoughts on the adoption and prescription of biosimilars in Japan from January to April 2020. We received totally 1024 responses. When adopting biosimilars and explaining them to patients, physicians requested specific information including the comparative results of phase III clinical trials and quality characteristics between biosimilars and their originators; the results of clinical studies on switching from originators to their biosimilars; and a comparison of the estimated cost on patients in consideration of the high medical cost payment system. Priority differed depending on the studied disease areas. In terms of post-marketing information, physicians requested a variety of information. When explaining biosimilars to the patients, physicians would like to use general material from government describing the comparability between originators and their biosimilars. These results suggest that physicians sought more comparative information on the quality, efficacy, and patients' cost between originators and their biosimilars when adopting or prescribing biosimilars.