Gene Therapy Program

Gene Therapy for Hemophilia A

Hemophilia A is a genetic bleeding disorder caused by a mutation in the F8 gene that leads to  low levels of a protein called factor VIII. Factor VIII is necessary for blood clotting. Severe hemophilia A can cause prolonged or spontaneous bleeding, particularly in the muscles and joints, or internal organs. The current standard of care for hemophilia A is to control or prevent bleeding episodes through factor replacement therapy, given by regular intravenous (IV) infusions.

How gene therapy for hemophilia A works

Gene therapy is designed to provide long-term expression of the missing or abnormal clotting factor to reduce — or even eliminate — the need for factor replacement therapy. In the laboratory, a normal F8 gene is packaged into a modified adeno-associated virus (AAV) that targets liver cells. This virus, which acts as a delivery vehicle, or vector, is introduced into a patient's body with a single intravenous infusion. The vector with the functional copy of the F8 gene then travels to the liver and enters the liver cells, enabling the body to make factor VIII.

Matt, who received gene therapy for hemophilia A, with his family

Meet Matt.

The magnitude, timing and durability of response to hemophilia A gene therapy is broad. After treatment, Matt's measurable factor levels, are now in the mild hemophilia range — a dramatic improvement from his severe disease, not only in terms of improved lab results, but also in his everyday life, and ability to enjoy his family and favorite activities.


Dana-Farber Boston Children's Cancer and Blood Disorders Center logo

The commitment and compassion with which we care for all children and families is matched only by the pioneering spirit of discovery and innovation that drives us to think differently, to find answers, and to build a better tomorrow for children everywhere.

Kevin B. Churchwell, President and CEO

Connect with Boston Children's Hospital