Emicizumab Shows Promise for Acquired Hemophilia A in Real-World Settings
A large retrospective study conducted across 12 US hemophilia treatment centers has demonstrated the real-world effectiveness and safety of emicizumab for patients with acquired hemophilia A (AHA), a rare and potentially life-threatening autoimmune bleeding disorder. The study, which analyzed data from 62 patients treated off-label with emicizumab, highlights the potential of this FVIII mimetic antibody to provide reliable bleeding prophylaxis and support outpatient care.
Emicizumab was initiated in most cases (95.2%) due to acute bleeding at diagnosis, with over 60% of patients having only partial or no bleed control from standard hemostatic agents. Its primary use was for outpatient prophylaxis, allowing patients to transition from inpatient to outpatient care more efficiently.
Following emicizumab initiation, 87.1% of patients experienced no further bleeding. Only 6 breakthrough bleeds occurred across 5 patients, and there were no fatal bleeding events during treatment. The mean breakthrough bleed rate was remarkably low at 0.02 per patient-week.
Most patients (92.7%) also received immunosuppressive therapy (IST), often with rituximab. Of those treated with rituximab, 63% achieved full inhibitor resolution and FVIII normalization. Median time to discontinue both emicizumab and IST was 18 weeks.
Importantly, no adverse events were attributed directly to emicizumab. Two thrombotic events occurred in patients with pre-existing vascular risk factors, but neither was linked to the treatment.
This study represents the largest cohort of AHA patients treated with emicizumab outside of clinical trials, according to the authors. Despite the older age and comorbidity burden typical of patients with AHA, emicizumab proved both safe and effective in real-world use.
Reference
Poston JN, Bryan C, von Drygalski A, et al. Real-world impact of emicizumab and immunosuppression on acquired hemophilia A: a multicenter US cohort. Blood Adv. 2024;8(22):5896-5905. doi:10.1182/bloodadvances.2024013882
