Dosing and Consumption of rFVIII Products with Extended Half-life in Patients with Hemophilia A in Real-World Practice

Introduction

In the United States, two rFVIII EHL products – efmoroctocog alfa (a fusion protein with the Fc fragment of IgG) and rurioctocog alfa pegol (pegylated recombinant antihemophilic factor) are used for hemophilia A prophylaxis and are also available in the Czech Republic. American authors retrospectively compared the weekly consumption of these products and their dosing frequency based on an analysis of data from the US Specialty Pharmacy Database from 2015–2018.

Patient Population

Enrolled patients had to have a diagnosis of hemophilia A, use efmoroctocog alfa or rurioctocog alfa pegol for prophylaxis for at least two consecutive months, and have known body weight. The number of doses per week, changes therein, and the weekly dose dispensed were evaluated.

The analysis included 774 patients, of which 506 were using efmoroctocog alfa and 268 rurioctocog alfa pegol. Their average age was 24.2 years in the efmoroctocog alfa group and 26.3 years in the rurioctocog alfa pegol group. The average body weight in these groups was 68.4 kg (standard deviation [SD] 36.8 kg) and 79.8 kg (37.7 kg), respectively. Most patients had severe hemophilia A.

Findings

Efmoroctocog alfa was most commonly administered 2× weekly (in 45.7% of cases), followed by every 4 days (20.6%), every 3 days (9.1%) or 3× weekly (7.5%). The most common dosing regimen for rurioctocog alfa pegol was also 2× weekly (in 72.4% of cases), followed by 3× weekly (8.7%), every 4 days (7.6%) or every 3 days (5.5%). During the follow-up, the proportion of patients using efmoroctocog alfa 2× weekly increased from 31.5% to 50.9%, and the proportion of patients with a dosing frequency every 4 days declined from 31.3% to 14.5% (over the period 2015–2018). The dosing regimen for rurioctocog alfa pegol remained largely stable according to drug dispensing data (2016–2018).

The average prophylactic weekly dose of efmoroctocog alfa was 105.4 IU/kg (SD 77.9; median 92.6 IU/kg), and for rurioctocog alfa pegol it was 96.8 IU/kg (SD 41.9; median 90.9 IU/kg).

Subgroup analysis showed higher consumption of efmoroctocog alfa compared to rurioctocog alfa pegol in the chosen year 2017 and in age groups both above and below 12 years.

Conclusion

This retrospective analysis expands the knowledge on the dosing and weekly consumption of recombinant factor VIII products with extended half-life in real-world practice among patients with hemophilia A without inhibitors. This can help physicians better understand the impact of the clinical effectiveness of these products. Data indicate that recombinant factor VIII products overall reduce disease burden due to less frequent administration.

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Source: Wu Y., Sun S. X., Fan T. Comparison of real-world dose and consumption for two extended half-life recombinant factor VIII products for the treatment of hemophilia A in the United States. J Blood Med 2022 Sep 24; 13: 517−524, doi: 10.2147/JBM.S359510.