FEIBA found to be safe, effective in severe hemophilia with inhibitors
Therapy lessens the number of bleeds in patients in real-world study
When given as a prophylactic, or preventive therapy, or on an on-demand basis, FEIBA (factor eight inhibitor bypassing activity) was deemed safe and effective at lessening the number of bleeds in people with severe hemophilia and high levels of inhibitors.
That’s according to four-year data from a real-world study. Its findings were reported in the study, “Real-world data in patients with congenital hemophilia and inhibitors: final data from the FEIBA Global Outcome (FEIBA GO) study,” published in the journal Therapeutic Advances in Hematology.
Hemophilia is a genetic blood disorder that affects the body’s ability to form blood clots, resulting in excessive bleeding. This happens due to the lack of specific blood clotting proteins. In hemophilia A, the missing clotting protein is factor VIII (FVIII), while in hemophilia B it is factor IX (FIX).
FEIBA, also known as activated prothrombin complex concentrate (aPCC) and anti-inhibitor coagulant complex, is a bypassing agent, given as an infusion, used as a preventive and on-demand treatment for hemophilia in patients with inhibitors, or neutralizing antibodies, against their missing blood clotting factors.
Originally developed by Baxter Healthcare and marketed by its spinoff Baxalta, which is now part of Takeda, FEIBA also is used to prevent and manage bleeds during surgery.
Safety, effectiveness of FEIBA tested in a real-world setting
The international, observational study FEIBA-GO (EUPAS6691) was designed to assess the safety and effectiveness of FEIBA, when used as on-demand or prophylactic treatment, in a real-world setting.
Here, researchers reported the outcomes of patients with hemophilia A or B and high levels of inhibitors who enrolled in FEIBA-GO.
In total, 51 male patients with a median age of 16.5 years from 11 countries were enrolled in the study. At the start of the study, 37 patients were receiving prophylactic treatment with FEIBA and 14 were using it on an on-demand basis.
From the initial pool of 51 patients, 11 completed the study and seven were followed for more than four years (48 months).
The safety analysis included the 37 patients who had been on preventive treatment and 13 who had been receiving on-demand treatment at screening. All had severe hemophilia and 49 had hemophilia A. High FVIII inhibitor titers were registered in 30 patients (68.2%).
The median number of weekly infusions was 4.12 in the preventive treatment group and 0.83 in the on-demand group. During the study, 16 patients, 11 of whom were on prophylactic treatment with FEIBA, underwent surgery.
The mean annual bleeding rate — or the mean number of bleeds occurring per year — was 6.82 in the 37 patients who were on FEIBA prophylaxis. Conversely, the 12 patients who received on-demand treatment had a mean annual bleeding rate of 10.94.
The same trend was seen regarding the mean number of annual bleeds occurring in the joints. Patients on preventive treatment had a lower mean number of joint bleeds occurring per year compared with those in the on-demand treatment group (3.77 vs. 6.94).
Some patients had no annual bleeds
Six patients on prophylaxis and two on on-demand treatment had no annual bleeds. No joint bleeds were reported in 11 patients on preventive therapy and four of those receiving on-demand treatment.
A bleeding event occurred in 31 patients (81.6%) receiving FEIBA prophylaxis, with 21 (55.3%) experiencing spontaneous bleeding episodes. Similar rates were seen in the on-demand treatment group, with 10 patients (83.3%) experiencing a bleeding event and nine (75%) a spontaneous bleed.
The majority of infusions in the prophylactic group (77.8%) were deemed “good” by patients and caregivers or researchers, with 18.2% being considered “excellent.” The same was reported for less than half of the infusions in the on-demand group, with 41.3% being rated “good” and 45.3% as “excellent.”
Overall, 177 adverse events were reported in 70% of the patients who were on FEIBA prophylaxis, and 31 in 76.9% of the patients who were receiving on-demand treatment. The most common were infections and musculoskeletal disorders.
One patient receiving prophylactic treatment had two serious adverse events, heart attacks, both possibly linked to FEIBA. No adverse events resulted in death.
The study also included 17 children, ages zero to 12 years, 14 of whom were on FEIBA prophylaxis and three were on on-demand treatment.
In the pediatric group, the mean annual bleeding rate was lower in the prophylactic than in the on-demand treatment group (12.32 vs. 16.77). The mean number of annual joint bleeds also was lower in the prophylactic treatment group (6.62 vs. 11.76).
No serious adverse events associated with FEIBA were reported in pediatric patients.
Overall, these findings “demonstrated the long-term, real-world effectiveness and consistent safety profile of aPCC as an on-demand therapy for the control of bleeding events and as a prophylactic treatment in patients with hemophilia and high-responding inhibitors,” the researchers wrote.
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