Abstract Number: PB0899
Meeting: ISTH 2020 Congress
Theme: Hemophilia and Rare Bleeding Disorders » Hemophilia - Clinical
Background: Long-acting recombinant factor VIII (FVIII) therapies provide additional therapeutic options to the previous armamentarium of standard-acting FVIII therapies. One such long-acting FVIII is rVIII-SingleChain. When evaluating different FVIII products in clinical practice, real-world utilization might be useful to optimize treatment outcomes.
Aims: To determine real-world dosing intervals, factor utilization and bleed rates in a group of Italian hemophilia A patients who switched from a prior FVIII product to rVIII-SingleChain.
Methods: Hemophilia Treatment Centers and hematologists provided de-identified patient chart information for 60 patients currently treated with rVIII-SingleChain. Data collected included age, sex, weight, current and prior treatment regimen (prophylaxis/on demand, infusion frequency, dosing), and number of reported bleeds. The dosing and infusion frequency on the patient’s most recent prescription were used to calculate prophylactic factor consumption with rVIII-SingleChain and the prior drug. The number of bleeds was annualized to calculate mean annual bleed rate (ABR) for rVIII-SingleChain, and over a period of up to 1 year on the prior drug.
Results: Of the 60 rVIII-SingleChain prophylaxis patients included in the study, 50.9% were dosed 2 or fewer times per week. Fifty-three (88%) patients were also treated prophylactically with their prior drug, with 54.7% of patients dosing at least 3-times per week. In these 53 prophylaxis-to-prophylaxis patients, mean prophylactic factor consumption (IU/kg/week) was similar with prior drug or rVIII-SingleChain (94.6 ± 38.5 and 95.0 ± 37.1, respectively). Mean ± standard deviation ABR decreased in this group of patients from 1.8 ± 1.7 (median, 1.0) with the prior drug to 0.5 ± 1.2 (median, 0.0) with rVIII-SingleChain. The percentage of patients with zero spontaneous bleeds went from 45.3% to 90.6% of patients.
Conclusions: This study shows that rVIII-SingleChain allows patients to use extended treatment intervals without increase in factor utilization and with effective bleed prevention consistent with clinical trial results.
| All patients (N=53) | Severe disease only (N=45) | |||
| rVIII-SingleChain (n=53) | Prior FVIII (n=53) | rVIII-SingleChain (n=45) | Prior FVIII (n=45) | |
| Age (years), mean (SD) | 32.5 ± 18.8* | 33.2 ± 18.3* | ||
| Dose, IU/kg/week ± SD | 95.0 ± 37.1 | 94.6 ± 38.5 | 96.6 ± 38.1 | 98.3 ± 40.1 |
| Prophylaxis dosing interval, % | ||||
| >2x/week | 49.1 | 56.6 | 51.1 | 62.2 |
| ≤2x/week | 50.9 | 43.4 | 48.9 | 37.8 |
| ABR, mean ± SD | 0.5 ± 1.2 | 1.8 ± 1.7 | 0.6 ± 1.2 | 1.8 ± 1.5 |
| AsBR, mean ± SD (zero spontaneous bleeds, %) | 0.3 ± 1.1 (90.6) | 1.1 ± 1.6 (45.3) | 0.3 ± 1.1 (91.1) | 1.1 ± 1.3 (42.2) |
| *Age only available for patients on current product; date of birth information not collected to ensure patient anonymity | ||||
[Table: Dosing, consumption and bleeding rates with rVIII-SingleChain and prior FVIII product for all prophylaxis-to-prophylaxis patients]
To cite this abstract in AMA style:
Mancuso ME, Santoro C, Maro G, Rives V, Sommerer P. Prophylactic Factor VIII Consumption and Clinical Outcomes in Italian Hemophilia A Patients who Switched to Extended Dosing Intervals with Long-Acting rVIII-SingleChain: A Retrospective Patient Chart Review [abstract]. Res Pract Thromb Haemost. 2020; 4 (Suppl 1). https://abstracts.isth.org/abstract/prophylactic-factor-viii-consumption-and-clinical-outcomes-in-italian-hemophilia-a-patients-who-switched-to-extended-dosing-intervals-with-long-acting-rviii-singlechain-a-retrospective-patient-chart/. Accessed October 1, 2023.« Back to ISTH 2020 Congress
ISTH Congress Abstracts - https://abstracts.isth.org/abstract/prophylactic-factor-viii-consumption-and-clinical-outcomes-in-italian-hemophilia-a-patients-who-switched-to-extended-dosing-intervals-with-long-acting-rviii-singlechain-a-retrospective-patient-chart/