Emicizumab is indicated for prophylaxis in persons with hemophilia A with or without factor VIII (FVIII) inhibitors to reduce or prevent bleeds. This study provides an early view of individuals treated with emicizumab, stratified by FVIII inhibitor status.
This study used commercial claims data from MarketScan Commercial Research (11/2016–12/2018) and PharMetrics Plus (11/2016–3/2019) Databases. To be included in the study, individuals were required to have evidence of emicizumab use, and to be continuously enrolled in the 12-month period preceding first emicizumab use. Demographics, clinical characteristics (major bleeds, arthropathy, and pain), utilization of FVIII and bypassing agents (BPA), and healthcare resource use were examined in the 12-month period preceding first emicizumab use. An algorithm developed by Shrestha et al. (2017) was used to identify major bleeds, defined as a cluster of bleeding claims for the same body part in a 7-day period.
A total of 107 patients with at least one emicizumab claim were identified. All patients were male (100%); average age was 24 years (standard deviation [SD]±17.6; range=1–62) with 17% (n=18) aged ≤5 years. In the 12-month period preceding first emicizumab use, 28% (n=30) had evidence of major bleeds, with an average of 2.2 bleeds (SD±1.9; range=1–8) among those with at least one major bleed; 17% (n=18) had evidence of arthropathy and related disorders, and 12% (n=13) had a diagnosis of pain. A total of 79% (n=85) had evidence of FVIII use and 17% (n=18) had a BPA claim (evidence of FVIII inhibitors) with an average of 10.3 (SD±12.3) and 8.6 (SD±7.9) prescriptions, respectively. Individuals with FVIII inhibitors were younger (mean age±SD: 18.0±13.3 vs. 25.4±18.2 years), and a larger proportion experienced major bleeds (44% vs. 25%), had evidence of arthropathy (44% vs. 11%) and pain (44% vs. 6%) compared to those without FVIII inhibitors. Of the 107 patients identified, 35% (n=37) had at least one emergency room visit (mean±SD=0.7±1.4); 14% (n=15) had at least one inpatient stay with mean length of stay of 1.1 (SD±3.5) days; 82% (n=88) had at least one outpatient hospital visit (mean±SD=4.1±9.7); and 88% (n=94) had at least one office visit (mean±SD=8.0±9.7). Generally, individuals with FVIII inhibitors had higher healthcare resource use compared to those without FVIII inhibitors.
To our knowledge, this is the first real-world claims study, which describes the characteristics of individuals initiating emicizumab, and underscores their disease and treatment burden. Results show utilization of emicizumab in patients with a broad range of clinical characteristics and across various age groups. Longer follow-up data will help to further examine these real-world outcomes.