Fewer Bleeding Events, Infusions with Extended Half‐Life Products for Hemophilia, European Survey Finds

Switching to extended half-life (EHL) products has provided a reduction in the number of infusions and fewer bleeding events compared to standard treatments, particularly in hemophilia B, according to early real-world data from Europe.

The study, “Real‐life experience in switching to new extended half‐life products at European haemophilia centres,” was published in the journal Haemophilia.

Therapies with EHL — meaning a longer time until the body reduces the blood level of clotting factor by half — are intended to provide less-frequent infusions, prolonged protection from bleeding, and improve patient compliance, compared to standard treatments.

As assessed by annualized bleeding rates (the number of bleeds per year), clinical trials have shown that EHL treatments for both hemophilia A and B are more effective that on-demand approaches. However, evidence from real-life use of EHL products remains limited.

Seeking to address this gap, a team from the U.K., Italy and Belgium analyzed data from 33 European hemophilia treatment centers (HTCs) belonging to the European Haemophilia Network (EUHANET), using a survey administered by the European Association for Haemophilia and Allied Disorders.

Notably, the survey was conducted at the beginning of 2018, when a limited number of EHL treatments were being marketed in Europe. Those included the hemophilia A therapy Eloctate (rFVIII‐Fc, by Sanofi Genzyme), the hemophilia B treatments Alprolix (rFIX‐Fc, also by Sanofi Genzyme) and Idelvion (rFIX‐FP, by CSL Behring), all recombinant coagulation factors —   FVIII, in the case of Eloctate, and FIX in Alprolix and Idelvion.

Each HTC was asked how long it had been using each therapy, what type of EHL product it had available, the percentage of patients who had switched to these treatments, as well as their benefits in terms of number of infusions, trough level (the lowest dose before the next dose is administered), and reduction of bleeding events.

The results revealed that Elocate was the EHL therapy routinely used in 25 (76%) of the centers, with more than half (55%) using it for more than a year. Among the other eight centers, six did not have access to Eloctate yet, while two (in Bulgaria and France) were not using the medication.

As for the EHL treatments for hemophilia B, 21 (64%) of the centers were using them regularly, 14 of whom had experience with both Alprolix and Idelvion. Thirteen centers (44%) had been using them for more than one year. Twelve centers were not using these therapies, either because they were not available in their countries or because they had not switched from standard treatment options.

Only two centers had switched at least 60% of their patients to Eloctate. Among 23 centers with available effectiveness data, 15 reported 30% or greater reduction in the number of infusions upon switching to EHL products, while four centers each reported decreases by 10% or 20%.

One-third of the 21 responding centers achieved a FVIII trough level of 1–3% and two-thirds achieved 3–5%. As for bleeding events, 12 centers (57%) had a decrease less than 20%, six (28%) within 20% and 50%, one center reported a 50-99% improvement, and two centers observed no bleeds.

Results in hemophilia B showed that only four of 21 centers had switched most (80-100%) of their centers to EHL therapies. All centers reported a decrease in infusions of more than 30%. The FIX trough level was at least 5% in 14 centers (67%), while four (19%) achieved 3-5% and three (14%) saw a 1‐3% level.

Five of 18 centers reported no bleeds upon switching to Alprolix and Idelvoin. Six centers found a 20-50% decrease and seven revealed a reduction under 20%.

Overall, the results show “a significant reduction in the number of infusions and a satisfactory trough levels in the clinical care of haemophilia patients, with a greater impact for haemophilia B,” the researchers wrote.

They added that a follow-up survey in the same centers with help monitor “the usage rate, efficacy and also the safety of these novel products.”