Objective:
We sought to explore real-world outcomes, such as annualized bleeding rate (ABR) and markers of adherence, in persons with hemophilia A (PwHA) or with hemophilia B (PwHB) who receive standard half-life (SHL) or extended half-life (EHL) factor VIII (FVIII) or factor IX (FIX) replacement products.
Methods:
We analyzed de-identified data from the Adelphi Disease Specific Programme (DSP) database, a patient health record–based survey of hematologists in the US and 5 European countries (France, Germany, Italy, Spain and the UK). Data were collected from May–November 2017 for male patients with moderate or severe HA or HB. Outcomes in the two groups of patients (SHL vs EHL) were compared and descriptive statistics were used to summarize results.
Summary:
A sample of 595 patients with HA or HB met the inclusion criteria (US, n=123; Europe, n=472). Age, weight, and body mass index (BMI) were similar between SHL and EHL groups for PwHA and PwHB on both continents. Higher ABR was noted consistently in Europe vs the US. Hemophilia A: Analysis included 101 patients from the US (SHL, n=64; EHL, n=37) and 360 patients from Europe (SHL, n=340; EHL, n=20). The ABR was similar between both groups on both continents (median: US, 1.0 SHL and 1.0 EHL; Europe, 1.0 SHL and 1.5 EHL; mean: US, 1.3 SHL and 1.2 EHL, P=0.68; Europe, 1.8 SHL and 1.7 EHL, P=0.76). The mean of the physician-reported ‘number of doses missed of the last 10 doses’ appeared to be numerically higher in the EHL vs the SHL group in the US (mean: 0.4 SHL and 1.6 EHL, P=0.13), whereas in Europe, the trend was reversed (mean: 0.7 SHL and 0.0 EHL, P=0.29). Hemophilia B: Analysis included 22 patients from the US (10 SHL; 12 EHL) and 112 patients from Europe (91 SHL; 21 EHL). The median ABR for PwHA and PwHB in the US was 1.0 (SHL) and 1.0 (EHL), and the mean was 1.6 SHL and 0.8 EHL (P=0.25); in Europe, the median ABR was 2.0 SHL and 1.0 EHL, and the mean was 2.2 SHL and 1.6 EHL, P=0.25. The mean of the physician-reported ‘number of doses missed of the last 10 doses’ was 0.8 SHL and 0.5 EHL (P=0.63) in the US and 0.6 SHL and 0.1 EHL (P=0.33) in Europe.
Conclusions:
These preliminary real-world data, unadjusted for treatment regimen and inclusive of US and ex-US sampling, showed no clinically meaningful difference in ABR or adherence markers in PwHA or PwHB who received SHL versus EHL FVIII or FIX products. These observations may challenge assumptions regarding adherence and or clinical outcomes associated with SHL/EHL product selection among PwHA and PwHB. Further analyses should be explored.