Real-World Analysis of Dispensed IUs of Coagulation Factor IX and Resultant Expenditures in Hemophilia B Patients Receiving Standard Half-Life Versus Extended Half-Life Products and Those Switching from Standard Half-Life to Extended Half-Life Products.

BACKGROUND

Hemophilia B requires replacement therapy with factor IX (FIX) coagulation products to treat and prevent bleeding episodes. A recently introduced extended half-life (EHL) recombinant FIX replacement product provided the opportunity to compare the amount of dispensed factor and expenditures for EHL treatment compared with a standard half-life (SHL) product.

OBJECTIVE

To determine factor international units (IUs) dispensed and expenditures associated with switching from nonacog alfa, the most commonly used SHL replacement product, to eftrenonacog alfa, an EHL FIX replacement product.

METHODS

Two U.S. claims databases were analyzed. A large national specialty pharmacy dispensation claims database was used to identify the number of IUs dispensed and monthly charges for all patients with hemophilia B from April 2015 to June 2016. Truven Health MarketScan Research Databases (January 2010-July 2016) were used to identify IUs and expenditures for patients with claims data for at least 3 months before and after switching from the SHL to the EHL product. Medians for IUs and expenditures are presented to accommodate for skewness of data distribution.

RESULTS

The national specialty pharmacy database analysis included 296 patients with moderate or severe hemophilia B (233 on SHL; 94 on EHL). Median monthly factor dispensed was 11% lower (2,142 IU) in the EHL versus SHL cohort over the study period, while individual monthly reductions ranged from 32% to 47% (9,838 IU to 16,514 IU). Using the wholesale acquisition cost, the median per-patient monthly factor expenditures over the 15-month study period were 94% higher ($23,005) for the EHL than for the SHL product. Individual median monthly expenditure differences ranged from 15% ($6,562) to 49% ($19,624). In the Truven database, 14 patients switched from the SHL to the EHL product. The amount of factor dispensed was variable; in the 1-year period before and after the switch from the SHL to the EHL product, mean IUs dispensed decreased by 3,005 IU, while median IUs dispensed increased by 4,775 IU. Factor replacement expenditures were higher after switching from the SHL to the EHL product in each of the 3-month periods examined before versus after the switch.

CONCLUSIONS

This analysis of real-world data showed that switching from the SHL to the EHL product was associated with higher expenditures. Increased expenditures noted in the first 3 months after switching may be related to initial stocking up of the EHL product, but expenditures were sustained throughout the 1-year period of data analysis. Further analysis of these findings with larger numbers of patients should be explored.

DISCLOSURES

This study was sponsored by Pfizer. Pfizer employees were involved in the study design; the collection, analysis, and interpretation of data; the review of the manuscript; and the decision to submit for publication. All authors are employees of Pfizer. No author received an honorarium or other form of payment related to the development of this manuscript. All authors participated in the study design, data interpretation, and manuscript review and revisions and granted approval for the submission of the manuscript. Alvir, McDonald, and Tortella also participated in data analysis. Data from this paper were presented in part at the European Association for Haemophilia and Allied Disorders Annual Meeting, February 1-3, 2017, Paris, France; at the International Society for Pharmacoeconomics and Outcomes Research Annual Meeting, May 20-24, 2017, Boston, MA; and at the International Society on Thrombosis and Haemostasis Congress, July 8-13, 2017, Berlin, Germany.