Key takeaways

  • Imaavy (nipocalimab-aahu) is a prescription drug approved to treat generalized myasthenia gravis (gMG) in adults and certain children.
  • Imaavy comes as an an intravenous (IV) infusion administered by a healthcare professional.
  • Typically, Imaavy is a long-term treatment.

Specifically, Imaavy is used in adults and children ages 12 years and older to treat generalized myasthenia gravis (gMG) in those who are anti-acetylcholine receptor (AChR) or anti-muscle-specific tyrosine kinase (MuSK) antibody positive.

To learn more about Imaavy’s uses, see the “Uses for Imaavy” section.

Imaavy basics

Imaavy contains the active ingredient nipocalimab-aahu.

Imaavy is a biologic medication. A biologic is made from parts of living organisms. It’s available only as a brand-name drug. It isn’t available in a biosimilar form.

Biosimilars are like generic drugs. Just as generic drugs can be an alternative to brand-name medications, biosimilars are an effective alternative to biologics.

Imaavy is used to treat gMG in adults and children ages 12 and older who are anti-acetylcholine receptor (AChR) or anti-muscle-specific tyrosine kinase (MuSK) antibody positive.

Myasthenia gravis is an autoimmune condition where your immune system mistakenly attacks healthy cells. This affects how well your nerves and muscles communicate with each other, which can cause muscle weakness, fatigue, difficulty moving, and other symptoms.

In people with gMG, the immune system mistakenly creates harmful antibodies (a specific type of protein called IgG) that attack receptors on the muscles.

Normally, your body produces antibodies constantly. It has a special system, called the neonatal Fc receptor (FcRn), that acts like a “recycling center” or security checkpoint. When antibodies float through your blood, this center grabs them and protects them from being destroyed. This helps them last longer in your system.

But Imaavy acts as a blocker for this recycling center. It attaches tightly to the FcRn checkpoint, preventing it from grabbing and saving the antibodies.

Because Imaavy blocks the recycling process, the body does not save the harmful antibodies. Instead, the body breaks them down and destroys them much faster than usual. This lowers the total number of harmful antibodies attacking your muscles, which leads to an improvement in symptoms.

Like most drugs, Imaavy may cause mild to serious side effects. The following lists contain some of the more common side effects Imaavy may cause, but they don’t include all possible side effects.

Keep in mind that side effects of a drug can depend on:

  • your age
  • other health conditions you have
  • other medications you take

Your doctor or pharmacist can tell you more about the potential side effects of Imaavy. They can also suggest ways to help reduce side effects.

Note: After the Food and Drug Administration (FDA) approves a drug, it tracks and reviews side effects of the medication. Sharing your experience helps make medications safer for everyone by giving doctors and researchers more information about how the drug works in real life. If you develop a side effect while taking Imaavy and want to tell the FDA about it, visit MedWatch or call 800-FDA-1088.

Mild side effects

Here’s a list of some of the mild side effects that Imaavy can cause. To learn about other mild side effects, talk with your doctor or pharmacist, or read Imaavy’s prescribing information.

Mild side effects of Imaavy that have been reported include:

Mild side effects of many drugs may go away within a few days to a couple of weeks. But if they become bothersome, talk with your doctor or pharmacist.

Serious side effects

Serious side effects from Imaavy can occur, but they aren’t common. If you have serious side effects from Imaavy, call your doctor right away. If you think you’re having a medical emergency, you should call 911 or your local emergency number.

Serious side effects of Imaavy that have been reported include:

Side effects in children

Typically, side effects in children are the same as those seen in adults.

Allergic reaction

For some people, Imaavy can cause an allergic reaction.

This side effect was reported in the drug’s studies.

In general, symptoms of an allergic reaction can be mild or serious.

What might help

If you have mild symptoms of an allergic reaction, such as a mild rash, call your doctor right away. They may suggest a treatment to manage your symptoms and can determine whether you should continue Imaavy treatment.

If you have symptoms of a severe allergic reaction, such as swelling or difficulty breathing, call 911 or your local emergency number right away. These symptoms could be life threatening and require immediate medical care.

If your doctor confirms you’ve had a serious allergic reaction to Imaavy, they may have you switch to a different treatment.

The Imaavy dosage your doctor prescribes will depend on your body weight in kilograms (kg). One kg is equal to about 2.2 pounds (lb).

Form and strength

Imaavy is available as a liquid solution that’s given as an intravenous (IV) infusion (an injection into your vein over a period of time). It comes in two strengths measured in milligrams (mg) per milliliter (mL):

  • 300 mg/1.62 mL (185 mg/mL) in a single-dose vial
  • 1,200 mg/6.5 mL (185 mg/mL) in a single-dose vial

Recommended dosages

Your doctor will prescribe the dosage of Imaavy that’s right for you based on your body weight in kg. Keep reading to learn more.

Dosage for gMG

For the initial dose of gMG treatment, your doctor will likely prescribe 30 mg per kg of body weight given as an IV infusion over the course of at least 30 minutes.

Additional doses (maintenance doses) begin 2 weeks after your initial dose and are 15 mg/kg. The IV infusions are given over at least 15 minutes. You will receive these doses every 2 weeks.

Children’s dosage

Imaavy is approved to treat gMG in children ages 12 years and older. The dosage for children is the same as for adults.

How to use

Your doctor will explain how Imaavy will be given to you. They’ll also explain how much you’ll be given and how often.

Imaavy is available as a liquid solution that’s given as an intravenous (IV) infusion (an injection into your vein over a period of time). You’ll receive infusions at a clinic or your doctor’s office.

About receiving Imaavy

The following are some common questions about using Imaavy.

  • What if I miss a dose of Imaavy? If you miss an infusion of Imaavy, you should receive your next one as soon as you can. You will continue to receive your doses every two weeks after that.
  • Will I need to use Imaavy long term? Imaavy is typically used as a long-term treatment. If you and your doctor determine that it’s safe and effective for your condition, you’ll likely use it long term.
  • How long does Imaavy take to work? In Imavvy’s clinical trials, it took 24 weeks to experience the drug’s full effects.

Imaavy can interact with several other medications. It can also interact with certain supplements as well as certain foods.

Before taking Imaavy, talk with your doctor and pharmacist. Tell them about all prescription, over-the-counter, and other drugs you take. Also tell them about any vitamins, herbs, or supplements you use. Sharing this information can help you avoid potential interactions.

Interactions with medications, foods, and supplements

The following table highlights medications, supplements, and foods that can interact with Imaavy. This list does not contain all drugs that may interact with Imaavy. If you have questions about interactions that may affect you, ask your doctor or pharmacist.

Medications that can interact with Imaavy• immunoglobulin products
• monoclonal antibodies
• antibody derivatives containing the human Fc domain of the IgG subclass (drugs that are shaped like the most common natural defense proteins in your blood)
Lab tests or vaccines that can interact with Imaavylive vaccines such as chickenpox vaccine (Varivax) or measles, mumps, and rubella (MMR)

Imaavy and alcohol

Alcohol is not known to interact with Imaavy. It’s likely safe to consume alcohol while taking Imaavy.

Whether you have health insurance or not, cost may be a factor when you’re considering Imaavy. What you’ll pay for Imaavy may depend on several things, such as your treatment plan and the pharmacy you use

Here are a few things to consider regarding cost:

  • Savings program: A program called Imaavy withMe may be available. For more information and to find out whether you’re eligible for support, call 800-526-7736 or visit the program website.

If you have questions about how to pay for your prescription, talk with your doctor or pharmacist.

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The following is important information to consider and discuss with your doctor or pharmacist before taking/using Imaavy.

Pregnancy and Imaavy

It’s not known whether Imaavy is safe to use during pregnancy. If you’re planning a pregnancy or can become pregnant, talk with your doctor before taking/using this drug.

Birth control and Imaavy

It’s not known whether Imaavy is safe to take during pregnancy. Therefore, if you’re sexually active and you or your partner can become pregnant, talk with your doctor about your birth control options while you’re using Imaavy.

Imaavy and breastfeeding

It’s not known whether Imaavy should be used while breastfeeding. If you’re currently breastfeeding or planning to do so, talk with your doctor before taking/using this drug.

Before taking Imaavy, discuss your health history with your doctor. Imaavy may not be right for you if you have certain medical conditions or other factors affecting your health. Be sure to talk with your doctor if any of the following apply to you:

  • current infection
  • upcoming vaccines and vaccination history
  • previous allergic reaction or hypersensitivity reaction to this or a similar drug
  • pregnancy
  • breastfeeding

Note: For more information about the potential negative effects of Imaavy, see the “Side effects of Imaavy” section.

Other drugs are available that can treat your condition. If you’d like to explore an alternative to Imaavy, talk with your doctor. They can tell you about other medications that might work well for you.

The following drugs are similar to Imaavy:

Disclaimer: While Healthline strives for factual, comprehensive, and current information, this article is not a substitute for a licensed healthcare professional’s expertise. Always consult a doctor before taking or discontinuing any medication. Drug information is subject to change and may not cover all uses, directions, precautions, warnings, interactions, reactions, or adverse effects. The lack of a warning does not guarantee a drug’s safety, effectiveness, or appropriateness for all patients or specific uses. Learn more about our approach to content integrity.