Prophylaxis able to reduce bleeds in older people with severe hemophilia
Four trials involving patients treated with extended half-life products analyzed
Preventive therapy, or prophylaxis, in patients ages 50 and older with severe hemophilia type A and type B was effective at reducing bleeds, including those in target joints, and improving some aspects of their quality of life.
That’s according to findings from a post hoc analysis of four Phase 3 clinical trials published in a letter to the editor titled, “Long-term clinical outcomes of prophylaxis with an rFVIIIFc or rFIXFc in adults aged ≥50 years with hemophilia A or B,” in Blood Advances.
Hemophilia occurs when certain clotting factors, that is, specific proteins required for blood clotting are lacking, factor VIII (FVIII) in hemophilia A and factor IX (FIX) in hemophilia B.
Preventive or prophylactic replacement therapy is considered the gold standard treatment. It involves administering the clotting factor patients are missing on a routine basis as preventive measure against bleeds.
Studies have shown these therapies must be administered early in life to be effective at preventing joint bleeds and preserving joint health in people with severe hemophilia, however. This means older hemophilia patients who didn’t receive this treatment from a young age may be at a higher risk of developing hemophilic arthropathy, a condition marked by pain and irreversible joint damage that occurs as a consequence of recurrent joint bleeds.
Annualized bleed rate reduced
Researchers analyzed four clinical trials involving patients with severe hemophilia A and B, ages 50 and older, who received treatment with extended half-life products to better understand the impact of prophylaxis when introduced later in life.
The hemophilia A patients had taken part in A-LONG (NCT01181128) and its ASPIRE (NCT01454739) extension study, while the hemophilia B patients were in B-LONG (NCT01027364) and its B-YOND (NCT01425723) extension. The extended half-life products tested included efmoroctocog alfa, a lab-made (recombinant) version of FVIII marketed as Elocta in Europe and as Eloctate in the U.S., Canada, and elsewhere, and Alprolix (eftrenonacog alfa), a recombinant FIX protein.
A total of 21 hemophilia A patients, with a median age of 57 at the start of the trial, that is, its baseline, joined A-LONG and 20 took part in ASPIRE. At baseline, 81% of these patients had target joints, meaning joints in which three or more spontaneous bleeds had occurred within three or six months.
There were 26 hemophilia B patients in B-LONG, with a median age of 56 at baseline. More than half (62%) had target joints and 16 joined B-YOND.
Before joining A-LONG, 29% of the patients were on prophylaxis and 71% received on-demand treatment. In B-LONG, 42% were given prophylaxis before enrolling, while 58% were on on-demand treatment.
Nearly half (48%) the patients in the A-LONG/ASPIRE trials and 62% in the B-LONG/B-YOND studies had at least one other health condition, such as high blood pressure and pain, and took at least one other medication.
With both types of hemophilia, prophylaxis reduced the overall annualized bleed rate (ABR) and the joint ABR, including in those with target joints at baseline, in patients ages 50 and older, the analysis showed. These reductions were more prominent in those who’d been receiving on-demand treatment because they had higher ABRs before entering A-LONG or B-LONG. The results were consistent with those seen in younger patients in the trials.
Joint health also improved. All 42 target joints present before treatment in 12 patients in A-LONG/ASPIRE and all 19 target joints in six patients in B-LONG/B-YOND resolved with prophylaxis.
Quality of life, as assessed by the Hemophilia Quality of Life Questionnaire for Adults, was sustained in patients, ages 50 and older, with both types of hemophilia, with improvements seen in domains like physical health, and sports and leisure. The findings suggest prophylaxis “may enable older [people with hemophilia] to be more physically active,” the researchers wrote. “Results for the subgroups of those aged [50 years and older] are consistent with the overall study populations, suggesting that [Eloctate] and [Alprolix] provide long-term clinical benefits irrespective of age or presence of target joints in [people with hemophilia].”
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