Real-World Health Care Expenditure In Hemophilia B Patients Using Standard And Extended Half-Life Recombinant Factor IX Products

Abstract

Management of hemophilia B includes replacement of factor IX (FIX) by intravenous infusion. The recent introduction of extended half-life (EHL) FIX products has enabled comparison of health care expenditure and volumes of factor dispensed for hemophilia B patients using either nonacog alfa, a standard half-life (SHL) or eftrenonacog alfa, an EHL FIX product. Data from a large, U.S. national specialty pharmacy database (April, 2015 to December, 2016) were used to identify direct expenditures and international units (IUs) dispensed for all patients who used nonacog alfa (SHL group) and/or eftrenonacog alfa (EHL group). The analysis was restricted to severe hemophilia B and prophylactic regimens only. Monthly averages were calculated for each patient considering the months in which the first and last prescriptions occurred, and intervening months. Descriptive statistics were used to analyze results. 151 patients meeting the above criteria were identified. The SHL group and EHL group comprised 101 and 75 patients, respectively; each group included 25 patients who had received both products during the study period. Median monthly average of FIX product dispensation was 26,050 IU (SHL) versus 15,412 IU (EHL) (p< 0.0001). Considerable variability was present in the range of monthly units dispensed in both groups (SHL, IQR 16,218 – 42,406 IU; EHL, IQR 10,897– 25,296IU). Median monthly expenditures were lower in the SHL group, 34,874 USD [IQR = 21,812-57,304] than in the EHL group, 45,673 USD [IQR = 31,621-74,505]; p=0.0031). Contemporary observations may be tailored through incorporation of clinical parameters into analyses of real-world claims data. This study suggests that contemporary SHL to EHL transitions incur a modest reduction in units dispensed and SHL to EHL transition is associated with increased expenditures. Further real world analyses incorporating larger numbers of patients should be explored.