PB0236 - Evaluation of real-world peri-operative outcomes in patients with haemophilia A (HA) with or without inhibitors on emicizumab prophylaxis in Australia

Background: Emicizumab, a recombinant bispecific monoclonal antibody, became routinely available in Australia in November 2020 as regular prophylaxis for patients with severe or moderate haemophilia A (HA) with and without inhibitors.

Aims: To evaluate real-world peri-operative outcomes in HA patients who have commenced emicizumab prophylaxis through retrospective data collection.

Methods: Data were extracted from the Australian Bleeding Disorders Registry (ABDR) regarding demographics, severity, treatment, inhibitors, number and type of surgical procedures in HA patients since commencing emicizumab. Further peri-operative detail was obtained from electronic medical record (EMR) review, including data on adverse peri-operative outcomes and emicizumab-specific FVIII levels.

Results: Data on 36 procedures performed in 26 HA patients on emicizumab treated through two different institutes [Alfred Health (AH) in Victoria and Fiona Stanley Hospital (FSH) in Western Australia] from 2020 to 2023 were available for analysis. 19/26 (73%) patients had severe disease. 7/26 (27%) had an inhibitor. Nearly all procedures were elective (35/36, 97%). 24/36 (67%) were minor procedures including 7 dental procedures, 5 intra-articular injections and 5 endoscopies. 12/36 (33%) were major operations, including 5 orthopaedic procedures. Tranexamic acid (TXA) was used in 10/24 (42%) minor and 8/12 (67%) major procedures. Factor replacement was used in 12/24 (50%) minor and 11/12 (92%) major procedures. Bypassing agents were used in 2/12 (17%) of the major procedures and none of the minor. Greater-than-expected bleeding occurred in 2/24 (8%) minor procedures and 1/12 (8%) major procedures. No thrombotic events occurred. Post-operative emicizumab-specific bovine FVIII level was monitored in 1/24 (4%) minor and 5/12 (42%) major procedures.

The study was approved by the Alfred Health Ethics Committee under the National Mutual Acceptance (NMA) scheme (87510).

Conclusion(s): Multi-centre real-world data on peri-operative outcomes suggest a reassuring safety profile for HA patients on emicizumab prophylaxis, in both minor and major procedures.