After gaining U.S. FDA priority approval for the first gene therapy to treat hemophilia B, CSL Ltd. reported long-term data from the pivotal HOPE-B trial that showed a single infusion of Hemgenix (etranacogene dezaparvovec-drlb) generated elevated and sustained mean factor IX levels and reduced the rate of annual bleeding. Presented at the American Society of Hematology (ASH) annual meeting on Dec. 10, data showed 24-month results reinforced the safety of treatment, with no serious treatment-related adverse effects.