PB0209 - Effectiveness and safety of efmoroctocog alfa (a recombinant factor VIII Fc) across body mass index (BMI) categories: pooled data from two non-interventional phase 4 studies (A-SURE/PREVENT)

Background: Factor VIII (FVIII) replacement therapy is the standard of care for hemophilia A. Efmoroctocog alfa, a recombinant FVIII Fc fusion protein (herein, rFVIIIFc), has an extended half-life allowing higher FVIII levels and a longer dosing interval than standard half-life products.

Aims: To evaluate real-world outcomes by body mass index (BMI) categories in persons with hemophilia A (PwHA) treated with rFVIIIFc in two observational studies.

Methods: Data on prophylactic treatment with rFVIIIFc were pooled from the Sobi-sponsored A-SURE (Europe, NCT02976753) and PREVENT (Germany, NCT03055611) phase 4 prospective observational studies. Only variables recorded in the same way for both studies were included. PwHA were grouped into underweight, normal, overweight, and obese categories by baseline BMI. Baseline demographics, characteristics, and presence of target joints were assessed. Annualized bleeding (ABR) and joint bleeding (AjBR) rates, length of prospective follow-up, injection frequency and weekly prescribed dose were recorded.

Results: A total of 321 PwHA with available BMI data were included in the following groups: n=8 (2.5%), underweight; n=175 (54.5%), normal weight; n=97 (30.2%), overweight; and n=41 (12.8%), obese. Baseline demographics/characteristics are summarized in Table 1. Due to the small sample size, data from the underweight group were not analyzed further. ABRs and AjBRs were similar between normal and overweight groups but slightly higher in the obese group (Table 2). Mean (SD) weekly injection frequencies were comparable in all BMI groups: 2.3 (0.6), normal weight; 2.4 (0.7), overweight; and 2.5 (1.0), obese. Mean (SD) weekly prescribed dose (IU/kg) declined with increasing BMI groups: 92.0 (39.8), normal weight; 79.5 (32.8), overweight; and 74.0 (35.1), obese.

Conclusion(s): These real-world data from two large observational studies support the use of rFVIIIFc prophylaxis in PwHA of all BMI categories. The numerically higher ABR and lower weekly dose/kg seen in the obese group might suggest the need for dose adjustment in this population.