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Gamifant

emapalumab-lzsg

Used for Immunodeficiency

Gamifant (emapalumab or emapalumab-lzsg) is the first medication approved for the treatment of a potentially severe inflammatory problem called primary hemophagocytic lymphohistiocytosis (HLH). It's given as an infusion through the veins (intravenously or IV) every 3 to 4 days by a healthcare provider.

Reviewed by:

Robert Chad Hakim, PharmD, BCCCP

Kristianne Hannemann, PharmD

Last reviewed on March 14, 2023

Basics Side effects Pros & cons Pharmacist tips FAQs Warnings Dosage References Prices Medicare

What is Gamifant (emapalumab)?

What is Gamifant (emapalumab) used for?

Primary hemophagocytic lymphohistiocytosis (HLH) that doesn't respond to conventional treatment, comes back, or worsens

How Gamifant (emapalumab) works

Gamifant (emapalumab) is a type of monoclonal antibody called an interferon gamma (IFNγ) blocking antibody. It works to lower inflammation by blocking a protein in the immune system called interferon gamma. This helps to improve inflammatory symptoms of primary HLH.

Drug Facts

Common BrandsGamifant

Drug Class Interferon gamma blocking antibody

Controlled Substance ClassificationNot a controlled medication

Generic StatusNo lower-cost generic available

AvailabilityPrescription only

What are the side effects of Gamifant (emapalumab)?

The following side effects may get better over time as your body gets used to the medication. Let your healthcare provider know immediately if you continue to experience these symptoms or if they worsen over time.

Common Side Effects

Infections (56%)
High blood pressure (41%)
Infusion-related reactions (fever, rash, redness, sweating; 27%)
Fever (24%)
Low blood potassium (15%)
Constipation (15%)

Other Side Effects

Stomach pain
Diarrhea
Rash
Cough
Fast heart rate
Fast breathing rate

Serious Side Effects

Contact your healthcare provider immediately if you experience any of the following.

Serious infection: fever, weakness, cough, difficulty breathing, diarrhea, stomach pain, sweating, chills, burning when you urinate, urinating more frequently

Source: DailyMed

The following side effects have also been reported

Side effects that you should report to your care team as soon as possible:

Allergic reactions—skin rash, itching, hives, swelling of the face, lips, tongue, or throat
Infection—fever, chills, cough, sore throat, wounds that don't heal, pain or trouble when passing urine, general feeling of discomfort or being unwell
Infusion reactions—chest pain, shortness of breath or trouble breathing, feeling faint or lightheaded
Stomach pain, unusual weakness or fatigue, nausea, vomiting, diarrhea, or fever that lasts longer than expected

Side effects that usually do not require medical attention (report these to your care team if they continue or are bothersome):

Pros and cons of Gamifant (emapalumab)

Pros

First treatment for primary HLH

Can use for people of all ages

Only given twice a week

Cons

Given as an infusion through the veins

Must be given by a trained healthcare professional

Not a cure for primary HLH; only lowers inflammatory symptoms of HLH

Pharmacist tips for Gamifant (emapalumab)

Make sure to mark your appointments on your calendar to see your provider to receive your Gamifant (emapalumab) doses or get blood work done. This can help you not miss any of your doses and allows your provider to make sure the medication is safe and working well for you.

Gamifant (emapalumab) is given as an infusion into the veins by trained healthcare professionals at a clinic or infusion center. The infusion will take about 1 hour. Make sure you know when your infusions are scheduled so you don't miss a dose.

Your provider will observe you during and after your Gamifant (emapalumab) infusion for reactions like fever, rash, redness, or sweating. These tend to be mild to moderate, and they typically get better when the infusion is slowed or stopped.

Gamifant (emapalumab) can raise your risk of developing an infection that can be serious or even life-threatening. If you develop symptoms of an infection (e.g., fever, cough, difficulty breathing, diarrhea, weakness, sweating, chills) after starting Gamifant (emapalumab), go to the hospital right away so you can be tested for an infection. If you have an infection, you might have to stop taking Gamifant (emapalumab) so your body can fight it off and fully recover.

Frequently asked questions about Gamifant (emapalumab)

What is primary hemophagocytic lymphohistiocytosis (HLH)?

Primary HLH is a rare, genetic problem that causes your immune system to be overly active, leading to inflammation. This causes several symptoms including fever, infection, rash, liver problems, seizures and other brain problems, lung problems, and blood cell problems. Primary HLH can progress quickly and be a life-threatening problem if not treated promptly. In studies, about half of the people with primary HLH weren't eligible for a stem cell transplant because of poor response to other HLH treatments. Gamifant (emapalumab) helps lower the activity of your immune system to help decrease symptoms. It can improve your condition and raise your chances of being able to get a stem cell transplant.

How well does Gamifant (emapalumab) work for primary HLH?

In clinical studies looking at how well the medication works, 63% of people with primary HLH had an improvement in their symptoms and lab values (e.g., blood cell and protein levels) after 8 weeks of Gamifant (emapalumab) treatment. Also, 70% of people taking Gamifant (emapalumab) were stable enough to receive a stem cell transplant.

How long do I have to take Gamifant (emapalumab)?

There isn't a specific amount of time that you'll need to take Gamifant (emapalumab). Since primary HLH is a genetic problem, you'll likely need to continue taking the medication as long as you're not having side effects, like infections and fever, it's helping your condition, and until you can receive a stem cell transplant. Discuss with your provider about how long you need to take Gamifant (emapalumab).

Do I need to take other medications with Gamifant (emapalumab)?

Yes. Your provider will give you certain medications before each dose of Gamifant (emapalumab) to prevent infections. These medications include an antiviral (e.g., acyclovir (Zovirax), valacyclovir (Valtrex)) for shingles prevention, an antibiotic (e.g., Bactrim (sulfamethoxazole / trimethoprim)) for Pneumocystis pneumonia prevention, and an antifungal (e.g., fluconazole (Diflucan)) for fungal infection prevention. Since Gamifant (emapalumab) lowers your immune system activity and your body's ability to fight off infections, it's important to take these medications because you're more likely to develop infections during treatment with Gamifant (emapalumab). You'll also need to take dexamethasone (a corticosteroid) once per day during Gamifant (emapalumab) treatment to help lower inflammation further. Speak with your provider if you have any concerns about taking these additional medications during treatment with Gamifant (emapalumab).

Can I take Gamifant (emapalumab) if I'm pregnant or breastfeeding?

If you're pregnant, thinking of getting pregnant, or breastfeeding, make sure to talk to your provider about the risks and benefits of using Gamifant (emapalumab). There haven't been any human studies done to know with certainty the safety of Gamifant (emapalumab) during pregnancy or breastfeeding. In animal studies, babies born to mothers exposed to Gamifant (emapalumab) during pregnancy weren't harmed. Additionally, there is only a little bit of evidence that shows levels of other monoclonal antibody medications like Gamifant (emapalumab) are low in breast milk. To be safe, discuss with your provider about whether it's possible to take Gamifant (emapalumab) while pregnant or breastfeeding.

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What are the risks and warnings for Gamifant (emapalumab)?

Gamifant (emapalumab) can cause some serious health issues. This risk may be even higher for certain groups. If this worries you, talk to your doctor or pharmacist about other options.

Infections

Risk factors: Active, long-term, or recurrent infection | Having other conditions that raise your risk of infection | Taking medications that weaken your immune system

Gamifant (emapalumab) can affect your body's ability to fight off infections. This can raise your risk of serious or life-threatening bacterial, viral, or fungal infections. Before starting Gamifant (emapalumab), you'll need to get tested for tuberculosis (TB) and get treatment if you test positive (meaning you have a confirmed TB infection). Then, during treatment, your provider will give you anti-infective medications before each Gamifant (emapalumab) dose to help lower your risk for infections. While taking Gamifant (emapalumab), go to the hospital immediately if you develop symptoms of an infection, like fever, cough, difficulty breathing, diarrhea, weakness, sweating, or chills. You'll need to get tested for an infection. You might have to stop taking Gamifant (emapalumab) so your body can fight the infection. Tell your provider about your medical conditions and medications so they can make sure Gamifant (emapalumab) is safe for you.

Might not be safe with some vaccines

You can still receive most vaccines, including the flu shot, while taking Gamifant (emapalumab). However, you shouldn't receive live vaccines while taking this medication and for at least 4 weeks after your last dose. This is because it's not known if they're safe for you while you're taking Gamifant (emapalumab). Examples of live vaccines include the FluMist Quadrivalent (live attenuated influenza vaccine), which is given through a nasal spray, and MMR (measles, mumps, and rubella vaccine). You should be brought up to date with all vaccines before starting Gamifant (emapalumab). Be sure to let your provider know you're taking Gamifant (emapalumab) before you receive any vaccines.

Gamifant (emapalumab) dosage forms

Typical dosing for Gamifant (emapalumab)

The typical dose is based on your body weight and is infused into the veins over 1 hour every 3 to 4 days. Your provider will adjust the dose based on how well it's helping your symptoms, your lab values, or if you're having side effects.

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References

Best studies we found

Centers for Disease Control and Prevention. (2021). Pneumocystis pneumonia.

Centers for Disease Control and Prevention. (2022). Live attenuated influenza vaccine [LAIV] (the nasal spray flu vaccine).

Immune Deficiency Foundation. (n.d.). Hematopoietic stem cell transplantation.

View All References (10)

LaHue, S. C., et al. (2020). Transfer of monoclonal antibodies into breastmilk in neurologic and non-neurologic diseases. Neurology(R) Neuroimmunology & Neuroinflammation.

Swedish Orphan Biovitrum AB (publ). (2023). Gamifant- emapalumab-lzsg injection [package insert]. DailyMed.

Swedish Orphan Biovitrum. (n.d.). Adapting to clinical response.

Swedish Orphan Biovitrum. (n.d.). Central to the cytokine storm.

Swedish Orphan Biovitrum. (n.d.). Discover the cytokine storm.

Swedish Orphan Biovitrum. (n.d.). Discover the data.

Swedish Orphan Biovitrum. (n.d.). Safety considerations.

Swedish Orphan Biovitrum. (n.d.). Target IFNγ to subdue the cytokine storm.

Swedish Orphan Biovitrum. (n.d.). Weathering the cytokine storm.

U.S. Food and Drug Administration. (2018). FDA approves first treatment specifically for patients with rare and life-threatening type of immune disease.

GoodRx Health has strict sourcing policies and relies on primary sources such as medical organizations, governmental agencies, academic institutions, and peer-reviewed scientific journals. Learn more about how we ensure our content is accurate, thorough, and unbiased by reading our editorial guidelines.

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