Addressing AAV Antibodies in Hemophilia B Gene Therapy: Wolfgang Miesbach, MD, PhD

“We can conclude, and this was a really surprising finding of the study, that in addition to patients with prior hepatitis B, prior hepatitis C and HIV infection, patients with preexisting antibodies to AAV, up to a certain titer, can be include in the study.”

Etranacogene dezaparvovec (EtranaDez, AMT-061; CSL Behring, UniQure) reduced annualized bleeding rate (ABR) in patients with hemophilia B, both with and without neutralizing adeno-associated virus vector antibodies, compared to superior to Factor IX (FIX) prophylactic therapy.

These findings, from the final analysis of the phase 3 HOPE-B study (NCT03569891), were presented by investigator Wolfgang Miesbach, MD, PhD, at the European Association of Haemophilia and Allied Disorders (EAHAD) 2022 Annual Meeting, February 2-4, 2022. Miesbach serves as professor and head of coagulation disorders at the Comprehensive Care Centre at University Hospital of Frankfurt, Germany.

Miesbach and colleagues found that, after a 6-month lead-in period, adjusted ABR was reduced by 64% (P = .0002) and FIX-treated bleeds reduced by 77% (P <.0001) over months 7 to 18. Almost all participants (98%) treated with the full dose of EtranaDez were able to discontinue prophylaxis.

CGTLive spoke with Miesbach to learn more about the demographics and findings from the HOPE-B study. He discussed the surprising finding that treatment was effective in participants with prior hepatitis B or C, HIV infection, or AAV antibodies.

REFERENCE

Final analysis of pivotal HOPE-B study demonstrates durable and sustained therapeutic effect of etranacogenedezaparvovec gene therapy in hemophilia B – Data presented at EAHAD 2022. News release. CSL Behring. February 4, 2022. https://www.cslbehring.com/newsroom/2022/hope-b-data-presented-at-eahad2022