Hemlibra Works to Reduce Bleeding Rates in Hemophilia A Children
“We demonstrate a successful experience with emicizumab prophylaxis and safe [surgical] approach with a focus on minimizing postoperative bleeding,” the researchers wrote.
The study, “Emicizumab in pediatric hemophilia: Bleeding and surgical outcomes from a single-center retrospective study,” was published in the journal Pediatric Blood & Cancer.
Hemlibra, marketed by Genentech, is an antibody designed to mimic the activity of factor VIII (FVIII) — the clotting protein that is defective in people with hemophilia A.
The medication, given by an under-the-skin (subcutaneous) injection, is approved to manage the symptoms of hemophilia A in people with and without inhibitors, which are neutralizing antibodies that can lower the efficacy of traditional replacement therapies.
“The use of emicizumab [Hemlibra] has been increasing in pediatric hemophilia treatment centers following demonstration of safety and efficacy in [hemophilia A] patients both with and without inhibitors,” the researchers wrote.
“However, there is limited real-world data to guide [surgical] management of pediatric [hemophilia A] patients receiving emicizumab prophylaxis,” they wrote.
To learn more, a pair of scientists at Texas Children’s Hospital, in Houston, examined the outcomes of 28 children with hemophilia A who received preventive (prophylactic) treatment with Hemlibra from 2018 to 2021. All but one of the children had severe hemophilia, and about half (46.4%) had inhibitors.
Most of the children were white (75%), and more than half were of non-Hispanic ethnicity (53.6%). Their median age at the time of the therapy’s start was 6.7; most of the children (78.6%) started receiving the medication before age 12.
Importantly, the vast majority of children — 24 of 28, or 85.7% — were on other preventive therapies prior to starting treatment with Hemlibra. The most common reasons for switching were patient/parent preference (39.3%) and the prior therapy not being effective (28.6%).
In the one to two years before starting on Hemlibra, the average annual bleeding rate (ABR) was 3.61 bleeds per year, and only two of the children were averaging zero bleeds per year. By contrast, after starting on Hemlibra, the average ABR dropped to 0.44 bleeds per year, and about two-thirds of the children (67.9%) had no bleeds.
Most of the children (85.7%) did not experience any unwanted treatment side effects, though a few experienced pain at or near the injection site.
Over the period of the study, seven children underwent surgeries. In keeping with the center’s practice, these children were given additional replacement therapies before and after surgery, while continuing on Hemlibra throughout.
“It is important to note that our [surgical] treatment approach uses more pre- and postoperative factor replacement, in addition to emicizumab [Hemlibra], compared to other studies,” the researchers wrote.
There were no serious bleeds reported for any of the seven surgeries. One minor bleed occurred that may have been linked with surgery, though the researchers said that event “occurred 9 days after the procedure and may have been secondary to trauma (child playing with siblings at home prior to symptom development) rather than the [surgery] itself.”
Another patient experienced a clotting-related health event called cephalic vein thrombophlebitis following surgery, which required factor replacement and other treatments to manage. Researchers noted that clotting-related issues “have been associated with emicizumab use.”
“Our center has had a successful experience with emicizumab prophylaxis in pediatric [hemophilia A] patients with a reduction ABR and minimal perioperative [near-to-surgery] bleeding symptoms following perioperative factor replacement,” the team concluded.