Abstract Number: PB0645
Meeting: ISTH 2021 Congress
Background: rIX-FP, a recombinant factor IX (rFIX) linked with recombinant human albumin, has demonstrated efficacy in prophylactic regimens up to every 21 days in patients with hemophilia B.
Aims: To describe real world experience for a rural pediatric patient during the COVID-19 pandemic.
Methods: Demographic, clinical (HEAD-US and Hemophilia Joint Health Score) and pharmacokinetic (PK) data were collected for up to one year following a switch from rFIX to rIX-FP.
Results: In May 2018, a 3-year-old patient (moderate hemophilia B, FIX: 2.7 IU/dL) experienced hemarthrosis in the left knee and initiated prophylaxis with rFIX (40 IU/kg 2×/week). In March 2020, the patient switched to weekly rIX-FP prophylaxis (40 IU/kg), due to difficulties with venous access and accessing the clinic during the pandemic. Trough levels of 7.7% two weeks post-infusion and 5.1% 20 days post-infusion were maintained. Functional and joint assessment on day 90 of rIX-FP treatment showed no change, and no FIX inhibitors developed. On day 95 of treatment, a post-traumatic otorrhagia subsided after a single 40 IU/kg dose of rIX-FP. On day 120, the treatment interval was extended to 10 days without complications. After 160 days, the patient was diagnosed with an asymptomatic SARS-CoV-2 infection and self‐isolated at home for 14 days with no changes to prophylactic treatment. On day 200, after a new PK study (trough levels of 6.9% at 14 days post-infusion), the prophylaxis interval was prolonged to 70 IU/kg every 14 days without incident. With 14-day dose intervals, monthly consumption reduced by 56.2% and the number of infusions by 75% compared with the initial rFIX treatment, without affecting efficacy or adherence.
Conclusions: Switching to rIX-FP in this pediatric patient reduced the number of administrations and clinic visits without affecting efficacy or adherence, a fact that is relevant in the current context of the pandemic.
To cite this abstract in AMA style:Díaz Jordan BL, Cebanu T, Álvarez Román MT. Real-world Experience of rIX-FP Prophylaxis at Dosing Intervals of up to 14 Days in a Pediatric Patient with Hemophilia B during the COVID-19 Pandemic [abstract]. Res Pract Thromb Haemost. 2021; 5 (Suppl 1). https://abstracts.isth.org/abstract/real-world-experience-of-rix-fp-prophylaxis-at-dosing-intervals-of-up-to-14-days-in-a-pediatric-patient-with-hemophilia-b-during-the-covid-19-pandemic/. Accessed September 23, 2021.
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