The impact of extended half‐life factor concentrates on prophylaxis for severe hemophilia in the United States

Abstract

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 ATHN‐dataset, 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 vs standard half‐life (SHL) products in severe hemophilia was compared between June 2018 and March 2019 using the ATHN‐dataset. A cohort of patients was also recruited from seven participating HTCs in order to compare ABR, HJHS and QOL between product classes.By March 2019 the number of individuals with severe Hemophilia A (SHA) receiving EHLs remained relatively stable (28.4%), whereas the number of 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 severe hemophilia B (SHB) received treatment with EHLs including 57.5% by March 2019. 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.

Factor product utilization and health outcomes in patients with haemophilia A and B on extended half‐life concentrates: A Canadian observational study of real‐world outcomes

“…The overall calculated factor utilization in the U.S. (based on median prescribed dose and number of anticipated infusions) appeared to be much higher than our Canadian data for both SHL and EHL FVIII/FIX. Despite country‐specific differences in factor utilization, ABR appeared comparable between our study and a recent U.S. study on the impact of EHL on utilization and bleeding outcomes 7 . In contrast, a recent single‐centre study from another public healthcare system (U.K.) reported comparable ABR between a low‐dose rFIXFc prophylaxis (mean 31 IU/kg/wk) and SHL FIX (dosing not reported), although the numbers reported were small (n = 13) 10 …”

Perceptions about the efficacy of extended half‐life (EHL) factor products in persons with haemophilia (PWH): A national survey of haemophilia providers from haemophilia treatment centres (HTCs) in the United States

“…Clearly substantial reduction in infusion burden with FIX-EHLs is critical for patients' QOL. 8 Moreover, the availability of non-factor therapies like emicizumab may be playing a role for PWHA. 11 Through the subsequent section, we sought to understand clinician preferences with laboratory monitoring of EHLs.…”

Clinical, humanistic, and economic burden of severe haemophilia B in adults receiving factor IX prophylaxis: findings from the CHESS II real-world burden of illness study in Europe

“…Patients with severe disease (factor IX level ≤ 1% IU/dL; FIX) experience frequent spontaneous and recurrent joint bleeds that, without appropriate treatment, lead to early arthritis, deformity, and other long-term complications [ 5 – 7 ]. The burden of haemophilia B remains substantial and persistent [ 8 – 11 ]. Improved outcomes also come with an inherent treatment burden, as treatments are administered 2–3 times per week for standard half-life (SHL) FIX or, more recently, every 1–2 weeks for extended half-life (EHL) FIX [ 12 , 13 ].…”