Abstract Number: PB0689
Meeting: ISTH 2022 Congress
Background: Individualized pharmacokinetic (PK)-guided prophylaxis has been shown to improve outcomes in patients with hemophilia A (PWHA) in clinical trials; however, the impact of PK-guided prophylaxis on FVIII consumption in real-world settings is poorly understood.
Aims: This retrospective chart review examined FVIII consumption and cost of treatment before and after PK-guidance in US hemophilia treatment centers (HTC).
Methods: This study included 132 male PWHA from 7 HTCs with moderate or severe disease, ≥3 months prior FVIII prophylaxis and up to 12 months FVIII prophylaxis after PK-guided prescription change (index date), no inhibitors prior to index date, and no concurrent participation in clinical trials. Changes in annualized bleed rate (ΔABR) and confidence intervals (CIs) were evaluated. Changes in mean weekly consumption of FVIII prophylaxis (ΔMWC; IU/kg/week) were estimated based on physician prescription with costs of prophylaxis estimated using Average Sales Price (Q3 2021) and annualized.
Results: Of the 132 patients (age: median = 13, range: 2-43; severe disease: 93.2%), 58 (44%) remained on the same FVIII (non-switchers) and 74 (56%) switched FVIII therapy (switchers) after PK assessment. Most switchers (95%) transitioned from standard half-life product (SHL) to extended half-life product (EHL), and 39/58 of non-switchers (67%) were on a SHL. ABRs decreased among all patients [-0.97 (95% CI:-1.54,-0.42)], with decrease more pronounced in non-switchers [-1.93 (-3.14, -0.78)]. MWC decreased among patients switching to EHL. While annual cost of therapy increased on average (related to higher per unit cost with EHL vs. SHL) (Table), 32% of patients had a decrease in annualized cost (Figure). Non-switchers had no significant change in MWC or cost of therapy.
Conclusion(s): PK-guided prophylaxis was associated with an overall ABR reduction in all patients. Many patients had similar or improved effectiveness without any increase in cost of therapy. PK guidance could be a useful and cost-effective strategy in the management of PWHA.
To cite this abstract in AMA style:Young G, Callaghan M, Balasa V, Soni A, Ahuja S, Roberts J, Simpson M, Frick A, Mokdad A, Xing S, Caicedo J. Effects of PK Assessment on FVIII Consumption and Estimated Costs for patients with moderate to severe Hemophilia A [abstract]. https://abstracts.isth.org/abstract/effects-of-pk-assessment-on-fviii-consumption-and-estimated-costs-for-patients-with-moderate-to-severe-hemophilia-a/. Accessed November 29, 2023.
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