Gene Therapy for Hemophilia B

Hemophilia B patients have an inherited gene mutation that impairs their ability to produce normal levels of a blood clotting factor called factor IX. This results in disabling or life-threatening bleeding, arising spontaneously or caused by trauma. Routine activities have the potential to cause prolonged bleeding, either externally or internally. Frequent sites of internal bleeding include the joints and muscles. 

The current standard of care involves frequent intravenous infusions of the factor IX protein.

Read more about the causes, symptoms, and diagnosis of hemophilia.

The goal of gene therapy for hemophilia B is improving the blood’s ability to clot, ideally over decades or for the rest of a patient’s lifetime. Gene therapy for hemophilia B is a one-time infusion that uses a vector to deliver a functional gene to replace the hemophilic patient’s own defective gene or a therapeutic gene to provide a missing protein. The result is better clotting factor activity to protect against bleeding.

In 2017, Lindsey George, MD, led the phase 1/2 trial for the first successful use of gene therapy with factor IX-Padua for near curative levels in hemophilia B.

At CHOP, the Novel Therapeutics for Bleeding Disorders (NoT Bleeding) Program, led by Dr. George, offers a gene therapy program for young adults with hemophilia B, as well as state-of-the-art clinical care.

FDA-approved gene therapies

In November 2022, the Food and Drug Administration approved Hemgenix, CSL Behring's hemophilia B gene therapy. Researchers at Children’s Hospital of Philadelphia are working on other types of gene therapies for hemophilia B with the goal of advancing treatment options for hemophilia B.

Clinical trials for hemophilia B

CHOP is one of the world’s foremost sites for pediatric research studies and clinical trials.

There are currently active gene therapy clinical trials for hemophilia B:  

• Check back for an up-to-date list of trials