Aim: To describe patient and treatment characteristics associated with bevacizumab BS-Pfizer, rituximab BS-Pfizer and trastuzumab BS-Pfizer and their reference products in Japan.Methods: This retrospective observational study used an administrative claims database to identify patients with ≥1 biosimilar or reference product prescription from 2019 to 2022 for approved indications. Descriptive statistics were calculated.Results: Overall, 14-39% of biosimilar-prescribed patients initiated therapy with reference products. Biosimilar utilization significantly increased from 2019 to 2022. The most-commonly prescribed concomitant class of therapy with biosimilars was antineoplastic therapy.Conclusion: Reference products were most frequently prescribed among the Japanese cohorts, but substantial and increasing proportions received biosimilars over time. Future studies should extend our initial insights to assess biosimilar clinical outcomes in Japanese settings.
Keywords: B-cell non-Hodgkin's lymphoma; Japan; bevacizumab; biosimilars; breast cancer; colorectal cancer; gastric cancer; non-small-cell lung cancer; real-world utilizationrituximab; trastuzumab.
This study examines the adoption of cancer biosimilar therapies in Japan from 2019 to 2022. Cancer biosimilars are complex treatments that closely resemble established cancer therapies already available in Japan. We looked into the characteristics of patients receiving three specific biosimilars – bevacizumab BS-Pfizer, rituximab BS-Pfizer and trastuzumab BS-Pfizer. We also investigated where patients received biosimilar treatment, other therapies they received alongside biosimilars and the proportion of patients using these therapies each year during the study. Our analysis utilized data from the ‘Medical Data Vision’ database, which records care provided in hospitals across Japan. We analyzed patient demographics and treatment patterns, and compared different groups using statistics to identify significant differences. Notably, we observed that between 14 and 39% of patients initially started treatment with the original version of the drug on the market, known as the ‘reference product,’ before switching to the biosimilar. Furthermore, our findings revealed a significant increase in the use of biosimilars each year during the study period. Biosimilars were most-commonly used alongside chemotherapy drugs. These initial findings shed light on the patient population using cancer biosimilars in Japan and the treatment contexts in which they are utilized. Future research should delve deeper into aspects such as cost of care, patient survival, side effects and other pertinent factors related to the use of biosimilars in cancer care in Japan.