Gamifant

Gamifant is a prescription medication used to treat primary hemophagocytic lymphohistiocytosis (HLH), a rare genetic disease characterized by life-threatening inflammatory symptoms. Symptoms may include fever, enlarged liver or spleen, cytopenia (decreased number of blood cells), and neurological abnormalities.

Gamifant belongs to a group of drugs called monoclonal antibodies. These work by binding to interferon gammas and neutralizing them. This results in decreased immune cell production. This medication is available in an injectable form to be given directly into a vein (IV) by a healthcare professional. Common side effects of Gamifant include possibility of infection, high blood pressure, and infusion-related reactions.

Gamifant is a prescription medicine used for the treatment of adults and children (newborn and older) with primary hemophagocytic lymphohistiocytosis (HLH), a condition which causes the body to make too many activated immune cells. Gamifant is intended for use in patients whose disease has come back or progressed, or other medicines have not worked well enough or cannot be tolerated.

This medication may be prescribed for other uses. Ask your doctor or pharmacist for more information.

Serious side effects have been reported with Gamifant. See the “Gamifant Precautions” section.

The most common side effects of Gamifant include the following:

• High blood pressure (hypertension)

• Fever

This is not a complete list of Gamifant side effects. Ask your doctor or pharmacist for more information. Tell your doctor if you have any side effects that bother you or that do not go away. Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Tell your doctor about all the medicines you take, including prescription and non-prescription medicines, vitamins, and herbal supplements. Especially tell your doctor if you take:

• Cytochrome P450 enzyme substrates like warfarin (Coumadin), amiodarone (Cordarone), acetaminophen (Tylenol), and many others

This is not a complete list of Gamifant drug interactions. Ask your doctor or pharmacist for more information.

Serious side effects have been reported with Gamifant including:

Infections. Gamifant is a medicine that affects your immune system and may lower the ability of your immune system to fight infections. Gamifant may increase your risk of serious infections that can lead to death. These infections include tuberculosis (TB), histoplasmosis, Herpes zoster infection (shingles) and other infections caused by viruses, fungi or bacteria that can spread throughout the body.

Your healthcare provider will:

• test you for TB before you start treatment with Gamifant.

• treat you with a medicine for TB if you at risk for TB or if you have a known positive TB test.

Infections are common in people treated with Gamifant. Before starting Gamifant, tell your healthcare provider if you:

• had TB in the past, or if you or a member of your family have been in recent close contact with someone with TB.

• have ever had a positive TB skin test (PPD).

• currently have or have had history of infections, including histoplasmosis or Herpes zoster (shingles).

• are being treated for an active infection.

• have symptoms of an infection, such as fever, sweat and chills, cough, breathing problems, blood in mucus (phlegm), warm, red, or painful skin or sores on your body.

Your healthcare provider will give you medicine to help prevent certain infections before you receive Gamifant. After starting Gamifant, tell your healthcare provider if:

• new symptoms of an infection appear.
• symptoms of an infection that you already had when starting Gamifant worsen.

Your healthcare provider will monitor you closely for signs and symptoms of infections during treatment with Gamifant.

Gamifant can cause serious infusion reactions. Infusion reactions are common with Gamifant, and can also be severe. Infusion reactions can happen during or shortly after treatment with Gamifant. Your healthcare provider may temporarily stop your infusion and treat your symptoms before continuing your infusion if you have severe infusion reactions. Tell your healthcare provider right away if you get any of the following symptoms:

• skin redness or itching
• fever
• rash
• excessive sweating
• chills
• chest pain
• shortness of breath
• nausea or vomiting 
• lightheadedness or dizziness

Do not take Gamifant if you are allergic to Gamifant or to any of its ingredients.

Medications can interact with certain foods. In some cases, this may be harmful and your doctor may advise you to avoid certain foods. In the case of Gamifant, there are no specific foods that you must exclude from your diet when receiving this medication.

Before taking Gamifant, tell your doctor about all of your medical conditions. Especially tell your doctor if you:

• have an infection 

• have received or are scheduled to receive an immunization (vaccine). You should not receive “live or attenuated-live” vaccines during your treatment with Gamifant and for at least 4 weeks after the last dose of Gamifant.

• are pregnant or plan to become pregnant. It is not known if Gamifant can harm your unborn baby.

• are breastfeeding or plan to breastfeed. It is not known if Gamifant passes into your breast milk. Talk to your healthcare provider about the best way to feed your baby during treatment with Gamifant.

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

Tell your doctor if you are pregnant or plan to become pregnant.

There are no well-done studies that have been done in humans with Gamifant. In animal studies, pregnant animals were given this medication, and the babies did not show any medical issues related to this medication. Talk to your doctor about risks to your unborn baby of using Gamifant.

Tell your doctor if you are breastfeeding or plan to breastfeed.

It is not known if Gamifant crosses into human milk. Because many medications can cross into human milk and because of the possibility for serious adverse reactions in nursing infants with use of this medication, a choice should be made whether to stop nursing or stop the use of this medication. Your doctor and you will decide if the benefits outweigh the risk of using Gamifant.

• You will receive Gamifant through a vein by intravenous (IV) infusion over 1 hour.

• Your healthcare provider will monitor you during the infusion for side effects.

• Gamifant is given 2 times a week (every 3 to 4 days).

• Your healthcare provider will do blood tests during your treatment with Gamifant to see how well you respond to treatment.

• Gamifant is used with another prescription medicine called dexamethasone. You can ask your healthcare provider for information about dexamethasone.

The dose your doctor recommends may be based on the following:

• the condition being treated
• other medical conditions you have
• other medications you are taking
• how you respond to this medication
• your weight

The recommended dose rage of Gamifant for the treatment of hemophagocytic lymphohistiocytosis (HLH) is weight-based starting at 1 mg/kg. The dose may be increased up to 10 mg/kg depending on response to the medication. The medication is to be administered via IV over 1 hour twice per week until hematopoietic stem cell transplantation (HSCT) is performed, too much toxicity occurs, or patient no longer needs treatment of HLH. 

If Gamifant is administered by a healthcare provider in a medical setting, it is unlikely that an overdose will occur. However, if overdose is suspected, seek emergency medical attention.

Keep all appointments with your doctor and the laboratory. Your doctor will order certain lab tests to check your body's response to Gamifant.