CSL Behring, the biopharmaceutical company behind the hemophilia B gene therapy HEMGENIX ® (etranacogene dezaparvovec-drlb), announced on March 17, 2026, a temporary global stockout of the therapy. This disruption means that some individuals in countries where HEMGENIX is commercially available may experience delays in accessing treatment.
Hemophilia B is a rare inherited bleeding disorder caused by deficiency of clotting factor IX. HEMGENIX is a one-time gene therapy approved for adults with hemophilia B who currently use factor IX prophylaxis therapy, have current or historical life-threatening bleeding, or have repeated serious spontaneous bleeding episodes. It was approved by the FDA in November of 2022.
CSL Behring has emphasized that the supply issue is not related to the safety or effectiveness of HEMGENIX but rather reflects the complexity of manufacturing gene therapies and the company’s “commitment to adhering to the highest regulatory and quality standards.” The company says it is working with regulatory authorities to ensure stable ongoing supply while maintaining those standards.
For people in the bleeding disorders community who have been planning or considering gene therapy, this news may raise understandable concerns. The National Bleeding Disorders Foundation recommends that anyone with questions or concerns about how this supply disruption may affect their care should contact their hemophilia treatment center (HTC) and providers with bleeding disorders expertise to help navigate your treatment options and plan accordingly.
The full statement from CSL Behring can be found on their website.
