First Interim Analysis of a 24-Month, Prospective, Non-Interventional, Multicentre Study in Germany Evaluating the Real-World Usage and Effectiveness of rFVIIIFc and rFIXFc in Patients with Haemophilia A or B (PREVENT)

C. Bidlingmaier¹, C. Heller², K. Schilling³, F. Langer⁴, W. Miesbach⁵, J. Oldenburg⁶, U. Scholz⁷, J. van den Boom⁸, H. Malmström⁹, B. Winding⁹, A. Tiede¹⁰

¹Dr. von Hauner's Children's Hospital, Paediatric Haemophilia Centre, Munich, Germany, ²University Hospital of Frankfurt, Department of Pediatric Hematology/Oncology, Frankfurt, Germany, ³University Hospital Jena, Department for Haematology and Medical Oncology, Jena, Germany, ⁴University Medical Centre Hamburg-Eppendorf, II. Medical Clinic and Polyclinic, Hamburg, Germany, ⁵Goethe University Hospital, Institute of Transfusion Medicine, Medical Clinic II, Frankfurt, Germany, ⁶University Clinic Bonn AöR, Institute of Experimental Haematology and Transfusion Medicine, Bonn, Germany, ⁷Center of Coagulation Disorders, Leipzig, Germany, ⁸Swedish Orphan Biovitrum, Martinsried, Germany, ⁹Swedish Orphan Biovitrum AB, Stockholm, Sweden, ¹⁰Hannover Medical School, Department of Hematology, Haemostaseology, Oncology and Stem Cell Transplantation, Hannover, Germany

Abstract Number: PB0952

Meeting: ISTH 2020 Congress

Theme: Hemophilia and Rare Bleeding Disorders » Hemophilia - Clinical

Background: The safety and efficacy of recombinant factor VIII Fc (rFVIIIFc) and recombinant factor IX Fc (rFIXFc) were demonstrated in pivotal Phase 3 trials in patients with severe haemophilia (PwH) A and B, respectively. The non-interventional PREVENT study provides data on the real-world usage and effectiveness of prophylactic treatment with rFVIIIFc and rFIXFc in Germany over a 24-month prospective period.

Aims: To report data from the first interim analysis of patients with at least 9 months prospective observation period from the ongoing PREVENT (NCT03055611) study in Germany.

Methods: PREVENT aims to enrol 200 PwH A and B from 25 centres. Previously treated patients who have been prescribed prophylactic treatment with rFVIIIFc or rFIXFc at enrolment are eligible. The primary endpoints are annualised bleeding rate (ABR), injection frequency and factor consumption. Additionally, secondary endpoints include reason for switch to rFVIIIFc or rFIXFc. Data are analysed employing descriptive statistics. Here, the analysis population includes all patients with at least one follow-up visit after 9 months from enrolment at the interim data cut, September 30th, 2019.

Results: The analysis population comprised 67 PwH A and 21 PwH B with a mean (SD) age of 26.2 (19.5) and 31.6 (20.7) years, respectively. Of these, 95.5% of PwH A and 76.2% of PwH B had severe haemophilia. The rFVIIIFc and rFIXFc treatment regimens remained unchanged in the majority of patients from enrolment until interim data cut (PwH A: 80.6%; PwH B: 57.1%). ABR, injection frequency, factor prescription, and treatment satisfaction are shown in table 1. The most common reason for switch was to reduce injection frequency while maintaining protection from bleeds (table 2).

Conclusions: The interim prospective analysis showed a low injection frequency while maintaining good protection from bleeds in PwH A and B treated with rFVIIIFc and rFIXFc prophylaxis, respectively. Physicians and patients were satisfied with rFVIIIFc/rFIXFc treatment.

	Haemophilia A (n=67)^a		Haemophilia B (n=21)^a
	n		n
ABR, median (Q1;Q3) mean (SD)	67	0.9 (0.0;2.4) 2.3 (6.2)	21	2.0 (0.6;3.1) 2.7 (3.1)
Joint ABR, median (Q1;Q3)	67	0.0 (0.0;1.3)	21	1.0 (0.0;2.1)
Weekly injection frequency, median (Q1; Q3)	66	2.2 (2.0;3.0)	21	1.0 (1.0;1.0)
Weekly dose (IU/kg/week), median (Q1;Q3)	63	85.8 (70.0;114.3)	20	41.8 (31.4;49.6)
Physicians satisfied/highly satisfied with treatment after 1 year, n (%)	53	46 (87)	17	15 (88)
Patients satisfied/highly satisfied with treatment after 1 year, n (%)^b	24	23 (96)	9	9 (100)
ABR, annualised bleeding rate ^aFor some of the outcomes data were not available for all patients at interim data cut. ^bCompletion of all patient reported outcomes was optional.

[Table 1. Prospective interim analysis data]

	Haemophilia A (n=67)	Haemophilia B (n=21)
Improve protection from bleeds, n (%)	23 (34.3)	2 (9.5)
Improve protection to increase physical activity level, n (%)	2 (3.0)	0 (0.0)
Reduce injection frequency while maintaining protection from bleeds, n (%)	42 (62.7)	19 (90.5)
rFVIIIFc, recombinant factor VIII Fc; rFIXFc, recombinant factor IX Fc

[Table 2. Reason for switch to rFVIIIFc/rFIXFc]

To cite this abstract in AMA style:

Bidlingmaier C, Heller C, Schilling K, Langer F, Miesbach W, Oldenburg J, Scholz U, van den Boom J, Malmström H, Winding B, Tiede A. First Interim Analysis of a 24-Month, Prospective, Non-Interventional, Multicentre Study in Germany Evaluating the Real-World Usage and Effectiveness of rFVIIIFc and rFIXFc in Patients with Haemophilia A or B (PREVENT) [abstract]. Res Pract Thromb Haemost. 2020; 4 (Suppl 1). https://abstracts.isth.org/abstract/first-interim-analysis-of-a-24-month-prospective-non-interventional-multicentre-study-in-germany-evaluating-the-real-world-usage-and-effectiveness-of-rfviiifc-and-rfixfc-in-patients-with-haemophili/. Accessed November 29, 2023.

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