Vyvgart (efgartigimod alfa-fcab) is a brand-name intravenous (IV) infusion prescribed for some adults with generalized myasthenia gravis. As with other drugs, Vyvgart can cause side effects, such as headaches and certain types of infections.

Vyvgart can cause certain side effects, some more common than others. These side effects may be temporary, lasting a few days to weeks. However, if the side effects last longer than that, bother you, or become severe, be sure to talk with your doctor or pharmacist.

These are just a few of the more common side effects reported by people who took Vyvgart in clinical trials:

* For more information about this side effect, see “Side effect specifics” below.

Mild side effects can occur with Vyvgart use. This list doesn’t include all possible mild side effects of the drug. For more information, you can refer to Vyvgart’s prescribing information.

Mild side effects that have been reported with Vyvgart include:

These side effects may be temporary, lasting a few days to weeks. However, if the side effects last longer than that, bother you, or become severe, be sure to talk with your doctor or pharmacist.

Note: After the Food and Drug Administration (FDA) approves a drug, it tracks and reviews side effects of the medication. If you develop a side effect during Vyvgart treatment and want to tell the FDA about it, visit MedWatch.

* For more information about this side effect, see “Side effect specifics” below.
† An allergic reaction is possible after receiving Vyvgart. To learn more, see “Side effect specifics” below.

Vyvgart may cause serious side effects. The information below may not include all possible serious side effects of the drug. For more information, you can refer to Vyvgart’s prescribing information.

If you develop serious side effects during Vyvgart treatment, call your doctor right away. If the side effects seem life threatening or you think you’re having a medical emergency, immediately call 911 or your local emergency number.

Serious side effects that have been reported in clinical trials include severe allergic reaction. To learn more about Vyvgart and allergic reaction, see “Side effect specifics” below.

Vyvgart may cause several side effects. Here are some frequently asked questions about the drug’s side effects and their answers.

Does Vyvgart have any long-term side effects?

Vyvgart isn’t likely to cause long-term side effects. There were no reports of long-term side effects in people receiving the drug in clinical trials. Most side effects of Vyvgart last only a few days or weeks. For details, see “Mild side effects” above.

If you have questions about long-term side effects with Vyvgart treatment, talk with your doctor.

How do the side effects of Vyvgart compare with Ultomiris?

Vyvgart and Ultomiris (ravulizumab-cwvz*) share some side effects, but there are also differences. Both Vyvgart and Ultomiris may cause headaches and upper respiratory tract infections such as the common cold.

As with Vyvgart, Ultomiris is a biologic drug that’s approved to treat generalized myasthenia gravis (gMG) in certain situations. (With gMG, muscle weakness affects several areas of the body.) Ultomiris is also approved to treat other conditions.

Side effects reported in clinical trials of Ultomiris include diarrhea and abdominal pain.† These side effects weren’t reported in Vyvgart’s clinical trials.

If you’d like to know more about how Vyvgart and Ultomiris compare, talk with your doctor. They can also help determine which medication is right for your condition.

* The reason “-cwvz” appears at the end of the drug’s name is to show that the drug is distinct from similar medications that may be created in the future.
† Ultomiris has a boxed warning for serious meningococcal infections such as bacterial meningitis. This is the most serious warning from the Food and Drug Administration (FDA). To learn more about this warning with Ultomiris, see this article.

Learn more about some of the side effects that Vyvgart may cause. To find out how often side effects occurred in clinical trials, see the prescribing information for Vyvgart.

Respiratory tract infection

Infections of the upper and lower respiratory tract may occur with Vyvgart treatment. Upper respiratory infections include the common cold, sinus infection, and more. Lower respiratory tract infections include bronchitis, pneumonia, and other illnesses.

Respiratory tract infections were one of the most common side effects reported by people who took Vyvgart in clinical trials.

Symptoms of a respiratory infection can include:

What you can do

It’s important to watch for any of the symptoms listed above during Vyvgart treatment. If you experience symptoms of a respiratory tract infection, notify your doctor. Your doctor may want you to schedule an office visit to determine the best treatment. If your infection is serious, they may temporarily pause treatment until the infection clears.

With your doctor’s approval, home remedies and over-the-counter medications such as pain relievers may help ease symptoms.

Urinary tract infection

Some people reported urinary tract infections (UTIs) in Vyvgart clinical trials. A UTI can involve any part of the urinary tract, including the urethra, bladder, and kidneys. These infections can develop from an overgrowth of bacteria after these germs enter the urinary tract.

Symptoms of a UTI include:

What you can do

Be sure to tell your doctor if you experience any of the symptoms above. Your doctor may want to test a urine sample to determine whether you have a UTI. If you have one, they’ll prescribe medication to treat it. If your infection is serious, they may pause your infusions until your infection clears up. (To learn more about Vyvgart infusions, see this article.)

Allergic reaction

As with most drugs, Vyvgart can cause an allergic reaction in some people. This side effect was rare in the drug’s clinical trials.

Symptoms of these reactions included:

  • skin rash
  • itching
  • flushing
  • swelling under your skin, typically in your eyelids, lips, hands, or feet
  • swelling of your mouth, tongue, or throat, which can make it hard to breathe

What you can do

You’ll receive Vyvgart infusions at your doctor’s office or infusion center. Your doctor will monitor you for an allergic reaction during and for a short period after your infusion. If you have a reaction, your doctor will stop the infusion. They’ll decide whether you should continue Vyvgart treatment.

For mild symptoms of an allergic reaction after your infusion appointment, call your doctor right away. They may recommend ways to ease your symptoms and determine whether you should continue receiving Vyvgart. However, if your symptoms are serious and you think you’re having a medical emergency, immediately call 911 or your local emergency number.

Be sure to talk with your doctor about your health history before you take Vyvgart. This drug may not be the right treatment for you if you have certain medical conditions or other factors that affect your health. These are considered drug-condition or drug-factor interactions. The conditions and factors to consider include:

Infections. Vyvgart treatment can increase the risk of certain infections. If you have an infection or symptoms of one, tell your doctor. They may delay or temporarily pause Vyvgart treatment until the infection clears. They may also prescribe medication to treat the infection.

Allergic reaction. If you’ve had an allergic reaction to Vyvgart or any of its ingredients, your doctor will likely not prescribe Vyvgart. Ask your doctor what other medications may be better options for you.

Pregnancy or breastfeeding. It’s not known whether Vyvgart is safe to take during pregnancy or breastfeeding. Before starting Vyvgart, tell your doctor if you’re pregnant or can become pregnant. You should also tell them if you’re breastfeeding or planning to do so while taking Vyvgart. They’ll help determine whether Vyvgart is safe for you and your child.

Alcohol consumption. If you drink alcohol, Vyvgart is likely safe for you. Talk with your doctor or pharmacist if you have any specific questions about how much alcohol you can safely drink during Vyvgart treatment.

Immunizations. Vyvgart may interact with certain vaccines, such as the measles, mumps, and rubella (MMR) vaccine. Before starting Vyvgart, be sure to talk with your doctor about any vaccines you may need. Your doctor will determine whether you should receive them before you begin Vyvgart treatment.

If you’d like to learn more about Vyvgart, talk with your doctor or pharmacist. They can help answer any questions you have about side effects from taking the drug.

Besides talking with your doctor, you can do some research on your own. These articles might help:

Disclaimer: Medical News Today has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.