Real-World Amount of Clotting Factor Concentrates Dispensed and Annual Medical Expenditures for Japanese Patients with Hemophilia B

Katsuyuki Fukutake,1,2 Kanae Togo,3 Linghua Xu,3 Leona E Markson,4 José Maria Jimenez Alvir,5 Ian Winburn,6 Toshiyuki Karumori3 1Laboratory Medicine, Tokyo Medical University, Shinjuku, Tokyo, Japan; 2Department of Blood Coagulation Diseases, Ogikubo Hospital, Suginami, Tokyo, Japan; 3Pfizer Japan Inc, Shibuya-ku, Tokyo, Japan; 4Pfizer Inc, Collegeville, PA, USA; 5Pfizer Inc, New York, NY, USA; 6Pfizer Ltd, Surrey, UKCorrespondence: Toshiyuki Karumori, Pfizer Japan Inc, Shinjuku Bunka Quint Bldg, 3-22-7, Yoyogi, Shibuya-ku, Tokyo, Japan, Tel +81-80-4152-4243, Email Toshiyuki.karumori@pfizer.comIntroduction: Until extended half-life (EHL) factor IX (FIX) concentrates became available in Japan in 2010, patients with hemophilia B received intravenous FIX replacement therapy with standard half-life (SHL) FIX concentrates.Purpose: To investigate the amount of factor dispensed and the associated medical expenditures for the treatment of hemophilia B in the real-world clinical setting in Japan.Methods: This retrospective study comprised patients with hemophilia B (N=197) who had filled prescriptions for FIX concentrates reported in Japan’s Medical Data Vision database from 2015 to 2019. Patients were included if they had 2 or more prescriptions for the same FIX concentrates within the first 6 months of the study period and the interval between prescriptions was at least 2 weeks.Results: Since 2015, there was a decrease in the proportion of patients using SHL FIX concentrates and a corresponding increase in international units of dispensed EHL FIX concentrates. Median annualized dispensed dosages (IU/kg body weight) of EHL FIX concentrates were lower than for SHL concentrates for outpatient use only. Annual total health care expenditures per patient and annual expenditures for prescribed FIX concentrates increased each year during the study period. Following a switch from an SHL to an EHL concentrate, the median amount of prescribed FIX concentrate decreased slightly, al