On Dec. 10, 2022, CSL announced data affirming the long-term durability and safety of single-infusion HEMGENIX® (etranacogene dezaparvovec-drlb) in the treatment of certain adults living with hemophilia B at the 64^th American Society of Hematology (ASH) Annual Meeting.

Results from the pivotal HOPE-B study, the largest gene therapy study in hemophilia B to date, demonstrated that after two years of follow-up, adults with severe or moderately severe hemophilia B treated with a one-time infusion of HEMGENIX generated elevated and sustained mean factor IX activity levels and durable hemostatic protection.

In the open-label, single-arm HOPE-B study, 54 adult male participants with severe or moderately severe hemophilia B, with or without pre-existing AAV5 neutralizing antibodies were infused with a single dose of HEMGENIX. HEMGENIX produced mean factor IX activity of 39.0 IU/dL at six months and 36.9 IU/dL at 18 months post infusion, which was sustained at 36.7 IU/dL in the long-term follow-up data at two years. In addition, 94 percent (51 out of 54) of patients treated with HEMGENIX discontinued use of prophylaxis and remained free of previous continuous routine prophylaxis therapy.