PB1289 - Real-world data of hemophilia A with inhibitor patients using emicizumab – 1st report in Korea

Background: Emicizumab is the first nonfactor drug developed and approved to mimic activity of factor VIII for hemophilia A patients. There is a limited experience of emicizumab in Asian population since to its late approval.

Aims: In Korea, emicizumab opened in market since January 2019, and got national insurance reimbursement since May 2020 for hemophilia A with inhibitor. Herein, we describe analysis of Korean hemophilia A patients with inhibitor using emicizumab.

Methods: From five centers who treat severe hemophilia A patients with inhibitor participated in the study. We included all patients in Korea who have more than 6 months experience of emicizumab use at the enrollment period.

Results: A total of 16 patients included 7 of pediatric patients and 9 adults. Their median age was 20.9 years old (range 1.4-48.3). Estimated annualized bleeding rate (ABR) of the patients was mean 14.1 with standard deviation of ± 14.2. Patients' demographics are summarized in Table 1. Median duration of the emicizumab use is 717.5 days (369-1788 days) in all subjects. (Table 2.) After emicizumab use, zero bleeding was achieved in nine patients (56.3%), and ABR was decreased to median 0 (0-1.47), mean 0.35 (± 0.49) in all patients. Annualized joint bleeding was median 0 (0-1.24), mean 0.11 (± 0.32) in all patients. Among 16 patients, one patient received two major surgery and one patient underwent minor operation. Major surgery was performed with three additional doses of rFVIIa for each surgery, and minor one without other replacement therapy except for emicizumab. Median emicizumab dose of the 16 patients checked at various time point was 51,450μg/mL (22,300-94,700).

Conclusion(s): Both adult and pediatric group resulted in similar efficacy with emicizumab treatment. All 16 patients had less than 1.5 ABR using emicizumab with various dosing schedules.