PB0672 - Real-World data on Hemophilia A patients switching to either BAY 94-9027 or BAY 81-8973 from Emicizumab using the ATHNdataset

Background: The ATHNdataset is a HIPAA-compliant, de-identified database sponsored by the American Thrombosis and Hemostasis Network, including 17,109 people with hemophilia A (PwHA). With the approval of Emicizumab for PwHA without inhibitors in 2018, a large number switched from standard half-life (SHL) or extended half-llfe (EHL) factor VIII (FVIII) products to Emicizumab. However, little is known about those individuals switching back to SHL or EHL products.

Aims: To evaluate the outcome of switching to either BAY 94-9027 or BAY 81-8973 from Emicizumab in PwHA in a real-world setting.

Methods: The ATHNdataset was queried for patients being treated with BAY 94-9027 and BAY 81-8973. Collected information included baseline demographic data, treatment history, and bleed rates. The data captured was between January 1, 2010 and April 30, 2022 .

Results: A total of 205 total patients were treating with BAY 94-9027 and 354 with BAY 81-8973.
Nine (4.4%) patients on Emicizumab switched to BAY 94-9027. Eight patients had severe disease, of which 3 were treating prophylactically, 1 underwent immune tolerance induction (ITI) and 4 were treating episodically. One patient had moderate disease and treated prophylactically. Prior to switching, the mean ABR while on Emicizumab was 0.25. After switching to BAY 94-9027, the mean ABR was 0 (Table 1).
Seventeen (5%) patients switched from Emicizumab to BAY 81-8973. For those 17, eleven patients had severe disease, of which one was treated prophylactically and 10 episodically. Five individuals had moderate disease, of which one was treated prophylactically and 4 episodically. One individual had mild disease and was treated episodically. Mean total ABR on Emicizumab was 1.5 vs 0.17 on BAY 81-8973. (Table 1)

Conclusion(s): In our study, PwHA without inhibitors treated prophylactically with Emicizumab who switched to either BAY 94-9027 or BAY 81-8973 in the real world essentially had no change in ABR before and after switching .