The Impact of Extended Half‐Life Factor Concentrates on Prophylaxis for Severe Hemophilia in The United States

: With licensure of extended half-life (EHL) factor products and the changing landscape of available hemophilia products, patients and providers have options for less treatment-intense prophylaxis. The impact of these products in clinical practice to date remains understudied. We aimed to quantify the use of EHL products in prophylaxis in the US using the ATHNdataset, a database of 145 ATHN-affiliated hemophilia treatment centers (HTCs). Further, we aimed to quantify the impact of EHL on key hemophilia indicators including annualized bleed rates (ABRs), hemophilia joint health scores (HJHS) and quality of life (QOL) metrics. The use of EHL versus SHL products severe hemophilia was compared between June 2018 and March 2019 using the ATHNdataset. A cohort of patients was also recruited from 7 participating HTCs in order to compare ABR, HJHS and QOL between product classes. By March 2019 the number of individuals with SHA receiving EHLs remained relatively stable (28.4%) whereas the number prescribed non-factor products increased to 7.1%, with a diminishing majority of patients (64.0%) continuing to receive SHLs. The majority of patients with SHB received treatment with EHLs including 57.5%. There was a trend toward lower ABR with use of EHLs in SHA and SHB, although this did not result in improved HJHS nor QOL. EHL use in the United States in severe hemophilia continues to increase, although at a slower rate in SHA with the availability of non-factor therapy. The impact of the EHL therapies in clinical practice should continue to be examined prospectively. This article is protected by copyright. All rights reserved.