Hemlibra may help active men with hemophilia A stay in the game
New study finds the therapy lessens bleeds and eases treatment burden
For physically active men with severe hemophilia A, switching from their standard preventive treatment to Hemlibra (emicizumab-kxwh) can help reduce bleeding, a recent study suggests. This change not only improved their quality of life but also reduced the burden of treatment, allowing them to maintain their active lives.
That’s according to data from a European Phase 4 clinical trial called HemiNorth 2 (EudraCT# 2020-003256-32), which also showed that Hemlibra was preferred by most participants over their standard factor replacement therapy. Most health-related quality-of-life metrics stayed consistent or improved after they switched to Hemlibra.
The study, “Health-Related Quality of Life, Physical Activity and Joint Health in People With Severe Haemophilia A Receiving Emicizumab: Results From the Phase IV HemiNorth 2 Study,” was published in Haemophilia. Roche, the company that develops and markets Hemlibra, sponsored the trial and study.
Understanding the two therapies
In hemophilia A, mutations in the F8 gene lead to problems with the production or function of FVIII, a protein crucial in blood clotting. This leads to the disease’s characteristic symptoms of unusually easy, prolonged bleeding. The condition is considered severe if FVIII activity levels are less than 1% of normal.
Factor replacement therapies work to control or prevent bleeding in people with hemophilia A by providing the missing FVIII. Hemlibra uses a different strategy, which involves binding to other clotting proteins to mimic the function of FVIII.
With these advancements in preventive treatment, the risk of bleeding and joint pain during exercise has decreased.
“The World Federation of Hemophilia guidelines now encourage [people with hemophilia] to engage in regular non-contact [physical activity] to maintain bone health, coordination, and good [quality of life],” the researchers wrote.
Despite this, people with hemophilia may still perceive physical activity as risky, which can negatively affect their quality of life, the researchers noted. In their study, they examined the experiences of men who switched from preventive FVIII replacement therapy to Hemlibra.
The participants, recruited from an observational study, had severe hemophilia A without FVIII inhibitors, which are neutralizing antibodies against clotting factors that may reduce a treatment’s efficacy. The 28 individuals recruited had also been receiving preventive FVIII replacement therapy. They then switched therapies and received under-the-skin injections of Hemlibra every one, two, or four weeks for 48 weeks (nearly one year). Of these, 25 completed treatment.
The investigators allowed participants to supplement Hemlibra with factor replacement before intense physical activity, but participants otherwise did not receive FVIII preventive treatment.
Patients were a median age of 26.5 years, and 12 were adolescents younger than 18.
Outcomes and participant feedback
Most quality-of-life factors — including perceived riskiness and the ultimate impacts of various activities — stayed relatively consistent. However, both adults and adolescents reported large, sustained decreases in treatment burden.
Additionally, a survey at week 49 found that 92% of participants, including all adolescents, preferred Hemlibra over their past treatment. Less frequent treatments were the main factor influencing this preference.
The median energy expended in vigorous or moderate activity also stayed relatively consistent during treatment, according to questionnaire results and Fitbit exercise tracking data in a subset of participants.
It was reassuring that participants’ physical activity didn’t decrease after the switch to Hemlibra, as this indicated their confidence in its protection against bleeds, the researchers wrote. Since they were already highly active, an increase in activity wasn’t expected.
Clinical results confirmed this confidence. Models showed that annual bleeds requiring treatment decreased from a mean of 5.9 to 1.6 per participant after the switch to Hemlibra. The number of participants with no bleeds requiring treatment also doubled during the Hemlibra treatment period, from 8 to 16.
Joint health remained largely unchanged, and no participants stopped using Hemlibra because of unwanted side effects. Nine participants experienced 15 adverse events likely related to treatment, with injection site reactions being the most common. No new safety concerns were reported.
Patient-reported results and clinical outcomes suggested that switching from preventive FVIII replacement therapy to Hemlibra was favorable. However, within this group, all participants had at least one joint or muscle bleed in the past year and had relatively high physical activity levels. As such, they might not represent the hemophilia A population more broadly, according to the team.
Another limitation of the study was the relatively short follow-up period. The researchers noted that “evaluation after a longer observation period would be valuable to determine changes in joint outcomes,” which might not have emerged in the 48-week study.
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