An Update on HEMGENIX® (etranacogene dezaparvovec-drlb) Availability

March 17, 2026

Dear Members of the Hemophilia B Community,

We are writing to share an important update regarding the availability of HEMGENIX® (etranacogene dezaparvovec-drlb), the gene therapy members of our community have been evaluating or preparing to receive.

CSL Behring has notified the hemophilia B community of a temporary global stockout of HEMGENIX®. We want to be absolutely clear: this situation is not related to the safety or effectiveness of HEMGENIX®. It reflects the inherent complexity of manufacturing gene therapies and CSL Behring’s unwavering commitment to the highest regulatory and quality standards. Importantly, CSL Behring has provided a formal commitment letter confirming their dedication to resuming full production and ensuring continued access to this therapy.

We understand that many in our community are in the process of pursuing gene therapy, a deeply personal and carefully considered decision. For those of you who are currently in evaluation, working with your treatment center, or in the midst of pre-treatment preparation: please do not pause your journey.

The Coalition for Hemophilia B strongly encourages all individuals who are in the evaluation or preparation phase to continue with your scheduled testing and assessments. Completing this process now means that when supply is restored, and it will be, you will be fully ready to move forward without delay. This is the most important step you can take right now to protect your access to this therapy.

We encourage you to:

•  Stay in close contact with your hemophilia treatment center (HTC) and care team.

•  Continue with all scheduled evaluations, lab work, and pre-treatment steps as directed.

•  Ask your care team about your specific timeline and how this temporary supply interruption may affect your plan.

•  Reach out to the Coalition for Hemophilia B if you have questions or need support navigating this situation.

The Coalition for Hemophilia B has been a steadfast advocate for this community for more than 35 years, and we remain fully engaged with CSL Behring and the broader hemophilia care network to monitor this situation closely. We are committed to keeping you informed with accurate, timely updates as they become available.

We know that the road to gene therapy is filled with hope, planning, and courage. A temporary supply interruption does not change what lies ahead. CSL Behring remains committed to this community, and so do we. Together, we will continue to ensure that every individual with hemophilia B has the support and information they need to pursue the care that is right for them.

With continued commitment,

Kim Phelan

Chief Executive Officer
Coalition for Hemophilia B