After one dose of gene therapy, hemophilia B patients maintain near-normal levels of clotting factor

Researchers are reporting the highest and most sustained levels to date of an essential blood-clotting factor IX in patients with the inherited bleeding disorder hemophilia B. After receiving a single dose of an experimental gene therapy in a clinical trial, patients with hemophilia produced near-normal levels of clotting factor IX, allowing them to stop clotting factor infusions and to pursue normal activities of daily life without disabling bleeding episodes.