Anouk Donners

129 Entire-vial dosing of emicizumab Two-tailed p-values of less than 0.05 were considered statistically significant. Statistical analyses were performed using IBM SPSS Statistics (IBM Corp. Released 2019. IBM SPSS Statistics for Windows, Version 26.0. Armonk, NY: IBM Corp), and graphics were made using GraphPad Prism (GraphPad Software LLC, Version 8.3.0, San Diego, CA, USA). RESULTS Baseline characteristics A total of 115 individuals treated with emicizumab were studied from July 2018 to January 2022. Three individuals were excluded, including one individual with type III Von Willebrand Disease and two individuals with acquired haemophilia A. The baseline characteristics are presented in Table 1; 112 PwHA were included in the studied cohort. Most (94%) of these PwHA had severe haemophilia A, 10 (9%) had FVIII inhibitors at baseline, and the median age was 24 (IQR 10−49) years. The cohort consisted of 80 adults/adolescents and 32 children, baseline characteristics according to age subgroup are presented in Supplemental Table ST1. Ten children started emicizumab therapy before the age of 3, including five previously untreated patients (PUPs), who started with emicizumab prophylaxis before FVIII exposure. Table 1. Baseline characteristics (n = 112) median (IQR) or n (%) Haemophilia A severity, n - Severe - Moderate - Mild 105 (94%) 5 (4%) 2 (2%) FVIII inhibitor present, n 10 (9%) Age in median years 24 (10−49) Body weight in median kg 70 (34−89) BMI in median kg/m2 24 (17−27) Previous therapy, n PwHA without inhibitors: - FVIII-SHL prophylaxis - FVIII-EHL prophylaxis - FVIII-SHL and -EHL on demand 50 (45%) 47 (42%) 5 (4%) PwHA with inhibitors: - rFVIIa prophylaxis - aPCC prophylaxis - rFVIIa and aPCC on demand 1 (1%) 2 (2%) 2 (2%) Previously untreated persons: 5 (4%) Abbreviations: aPCC: activated prothrombin complex concentrate; BU: Bethesda Units; EHL: extended halflife; FVIII: factor VIII; IQR: interquartile range; n: number; PwHA: persons with haemophilia A; SHL: standard half-life; rFVIIa: recombinant, activated factor VII; U: dosage units. 7