Emicizumab in Acquired Hemophilia A: A Real-World Case Series with Patient-Level Outcome Analysis

Background: Acquired hemophilia A (AHA) is a rare bleeding disorder caused by factor VIII inhibitors. Standard therapies are limited by thrombotic risk and prolonged hospitalization. Emicizumab, approved for congenital hemophilia A, has emerged as a potential alternative in AHA based on case reports and early clinical trial data. Objectives: To evaluate the efficacy and safety of emicizumab in AHA through a retrospective real-world case series and a systematic literature review with patient-level data analysis. Methods: We retrospectively analysed five AHA cases treated with Emicizumab at two Italian centres and performed a PRISMA-compliant systematic review of published reports, extracting and analysing patient-level data using JBI tools. Results: In the real-world cohort, early emicizumab use in five patients with high-titer inhibitors and severe bleeding led to rapid hemorrhagic control, early withdrawal of bypassing agents, and no thrombotic or adverse events. All the five patients received immunosuppression and inhibitor eradication was achieved in 60% of patients but for 40% follow up is still ongoin. The literature review identified 24 patients from 18 publications. Early emicizumab administration (at admission) was associated with reduced bleeding recurrence (0% vs. 56.3%), shorter in-hospital stay (median 23.5 vs. 39 days), and lower bleeding-related mortality (0% vs. 12.5%) compared to delayed administration. Conclusions: Early emicizumab initiation appears to be a safe and effective strategy for AHA management, particularly in fragile or high-risk populations. Its subcutaneous route, favourable safety profile, and ability to reduce hospitalization support its integration into first-line therapeutic algorithms. Further prospective studies are warranted to define.