Hemgenix is a one-time gene therapy for the treatment of adults with hemophilia B.

Hemophilia B is an inherited bleeding disorder resulting from missing or insufficient levels of blood clotting Factor IX, a protein needed to produce blood clots to stop bleeding.

Hemgenix consists of a viral vector that carries a gene for Factor IX. The gene is expressed in the liver to produce the Factor IX protein, which increases the blood levels of Factor IX to limit episodes of bleeding. 

What is Hemgenix used to treat?

Hemgenix is used to treat hemophilia B in adults who currently use Factor IX prophylaxis therapy, or who have current or historical life-threatening bleeding, or who have repeated, serious spontaneous bleeding episodes.

Symptoms of hemophilia B can include prolonged or heavy bleeding after an injury, surgery, or dental procedure; or may even occur spontaneously in severe cases. Prolonged bleeding episodes can lead to serious complications, such as bleeding into joints, muscles or internal organs, including the brain. 

Hemgenix works to reduce the rate of annual bleeds in hemophilia B patients, and reduce or eliminate the need for prophylactic therapy by generating elevated and sustained factor IX levels for a period of years after a one-time infusion.

Hemgenix may cause serious side effects, including:

Infusion reactions. Signs and symptoms of infusion reactions may include:

• chest tightness
• headaches
• abdominal pain
• lightheadedness
• flu-like symptoms
• shivering
• flushing
• rash, and
• elevated blood pressure.

You will need to be monitored while you are receiving the infusion, and for at least 3 hours after. If a reaction occurs, the infusion rate may be slowed or interrupted, then re-started at a slower rate.

Elevation of certain liver enzymes. You will need tests to assess the health of your liver before you receive Hemgenix, and then weekly blood tests to monitor your liver enzymes for 3 months after receiving the infusion. If you have preexisting risk factors for liver cancer, you will receive regular liver health testing for 5 years.

Hemgenix is not intended for administration in women.

Your healthcare provider will give you Hemgenix through an intravenous (IV) line.

The amount of time needed for the infusion will depend on your body weight.

Hemgenix can only be administered once.

Your doctor will monitor you for infusion reactions while you are receiving Hemgenix and for at least 3 hours after the infusion is complete. If an infusion reaction occurs, the doctor may slow or stop the infusion, resuming at a lower infusion rate once the symptoms resolve.

Usual Adult Dose for Hemophilia B:

2 x 10¹³ genome copies (gc) per kg of body weight

Comment:
-administer as an intravenous infusion after dilution with 0.9% normal saline at a constant infusion rate of 500 ml/hour (8 mL/min).

Use:
-treatment of adults with Hemophilia B (congenital Factor IX deficiency) who currently use Factor IX prophylaxis therapy, or who ave current or historical life-threatening hemorrhage, or who have repeated, serious spontaneous bleeding episodes.

Before you receive Hemgenix:

• you will be tested for Factor IX inhibitors. If the test result is positive, a retest will be performed 2 weeks later. You will NOT be able to receive Hemgenix if both tests are positive.
• you will also be tested to check the health of your liver.

Small amounts of Hemgenix may be present in your blood, semen, and other excreted/secreted materials, and it is not known how long this continues.

You should not donate blood, organs, tissues, or cells for transplantation after receiving Hemgenix.

Hemgenix may cause serious side effects.

• See Important information.

The most common side effects include:

• liver enzyme elevations
• headache
• elevated levels of a certain blood enzyme
• flu-like symptoms
• infusion-related reactions
• fatigue
• nausea, and
• feeling unwell.

These are not the only side effects possible. Tell your healthcare provider about any side effect you may experience.

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Tell your healthcare provider about all the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements.