Introduction and Objective:
Limited information exists in the recent literature capturing real- world utilization and cost of bypassing agents among hemophiliac patients with inhibitors in the US. The present study compared the cost of on-demand and prophylaxis treatment between aPCC and rFVIIa among inhibitor patients with severe hemophilia.
Methods:
A retrospective analysis of two large US specialty pharmacy databases was conducted using dispensing data over a 28-month period (Jan. 2012 to April 2014). Subjects were included if they had a diagnosis of hemophilia A or B (ICD-9 code 286.0 or 286.1) that was classified as severe and ≥12 months of consecutive prescription claims for only bypassing agents. For patients who switched between bypassing agents or between on- demand (OD) and prophylaxis (P) during the observation period, observations of ≥6 months with consistent prescriptions were selected and analyzed independently. Bypassing agent utilization was annualized and normalized by patient weight (kg). Cost was calculated using 2013 Redbook® US wholesale acquisition costs (aPCC=$1.81/U and rFVIIa=$1.77/μg) and compared by product and regimen using non-parametric statistics.
Results:
A total of 78 subjects with 84 observations met the inclusion criteria. Median age was 20 years old (range 2-64) and median time between the first and last prescription filled was 20.5 months. Approximately 34.5% of the subjects were on aPCC (44.8% [OD] and 55.2% [P]) and 40.5% were on rFVIIa (85.3% [OD] and 14.7% [P]). The remaining subjects (25%) were on various combinations of aPCC and rFVIIa. Median annualized utilization for aPCC and rFVIIa was 7,183U/kg (2,186U/kg [OD] and 9,612U/kg [P]) and 13,838μg/kg (9,493μg/kg [OD] and 27,245μg/kg [P]), respectively. Median annualized cost/kg was significantly lower (p=0.0071) among patients treated on-demand with aPCC ($3,956/kg) compared to rFVIIa ($16,801/kg). Similarly, median annualized cost/kg was also significantly lower (p=0.0093) among patients treated prophylactically with aPCC ($17,399/kg) compared to rFVIIa ($48,223/kg). Overall, median annualized cost/kg for on-demand and prophylaxis treatments was 76.5% and 63.9% lower, respectively, with aPCC compared to rFVIIa. Furthermore, there was no significant difference (p=0.6438) in median annualized cost/kg between aPCC prophylaxis and rFVIIa on-demand.
Conclusion:
Overall, these data suggest that the annualized treatment cost with aPCC is significantly lower compared to that of rFVIIa for both on-demand and prophylaxis regimens. For each patient treated on-demand or prophylactically with rFVIIa, approximately 3-4 patients could be treated with aPCC at comparable cost. Additionally, the median rFVIIa on- demand patient could be prescribed aPCC prophylactically to reduce bleeding episodes without significant cost implications.