Concomitant emicizumab prophylaxis and immune tolerance induction (ITI) may be suitable for bleeding prevention in pediatric patients with severe hemophilia A and inhibitors, according to a retrospective analysis.
“The primary objective of this study [was] to review a case series of pediatric patients with hemophilia A and inhibitors at our institution who have received emicizumab concurrently with ITI,” wrote, of Emory University in Atlanta, and her colleagues. The results of the study were reported in .
The case series included seven pediatric patients with severe hemophilia A who received concurrent emicizumab for bleeding prevention and ITI for inhibitor eradication. Data were collected from electronic medical records at a single hemophilia treatment center from Aug. 1 to Dec. 1, 2018.
The researchers included male patients from 0 to 21 years old who had titres greater than 0.6 chromogenic Bethesda units (CBU) per mL on two instances more than 2 weeks apart.
The treatment protocol, termed the “Atlanta Protocol,” used a novel dosing regimen, established using provider consensus, for the concomitant use of ITI and emicizumab.
After analysis, the researchers found that three patients attained a negative inhibitor titer of less than 0.6 CBU/mL, and two patients had a normal factor VIII recovery of greater than or equal to 66%.
In total, nine bleeding events were observed in four patients; however, no thrombotic events were reported. All patients continued on concomitant therapy at the point of data analysis.
The researchers reported that six patients used three different recombinant factor VIII products at 100 IU/kg, three times each week. The remaining patient used a plasma‐derived factor VIII product at an initial dose of 50 IU/kg, three times each week.
The small sample size, retrospective design, and short follow‐up period were key limitations of the study.
“Prospective studies will be necessary to compare treatment outcomes of ITI and emicizumab to other ITI regimens and to investigate whether emicizumab modifies the immunologic response to FVIII,” the researchers wrote.
No funding sources were reported. The authors reported financial affiliations with Bayer, Bioverativ, CSL Behring, Catalyst Biosciences, Genentech, HEMA Biologics, Novo Nordisk, Octapharma, and several others.
SOURCE: Batsuli G et al. Haemophilia. 2019 Aug 2.