On Nov. 22, 2022, the U.S. Food and Drug Administration approved the investigational gene therapy etranacogene dezaparvovec or Hemgenix to CSL Behring to treat adults with hemophilia B, making it the first gene therapy option for people living with the genetic bleeding disorder.

Hemophilia B occurs when genes that are vital to producing clotting factor IX are faulty, resulting in prolonged external or internal bleeding in the body. Without the ability to effectively stop bleeding, a simple cut or bruise can lead to external bleeds, and internal bleeding inside joints and muscles can damage organs including the brain.

Hemgenix works by delivering a functional copy of the faulty gene into a cell, instructing the cell to produce the missing clotting factor IX which helps control bleeding.