Efgartigimod Alfa Side Effects

Medically reviewed by Drugs.com. Last updated on Jan 12, 2024.

Applies to efgartigimod alfa: intravenous solution.

Precautions

It is very important that your doctor check your progress at regular visits to make sure that this medicine is working properly. Blood tests may be needed to check for unwanted effects.

Call your doctor right away if you start to have a cough that would not go away, weight loss, night sweats, fever, chills, flu-like symptoms (eg, runny or stuffy nose, headache, blurred vision, or feeling generally ill), painful or difficult urination, or sores, ulcers, or white spots in the mouth or on the lips. These may be signs that you have an infection.

This medicine may cause serious allergic reactions, including angioedema, which can be life-threatening and require immediate medical attention. Tell your doctor right away if you have a large, hive-like swelling on face, eyelids, lips, tongue, throat, hands, legs, feet, or sex organs, itching of the skin, rash, or trouble breathing after using this medicine.

While you are being treated with efgartigimod alfa-fcab, do not have any immunizations (vaccines) without your doctor's approval. Live virus vaccines should not be given with efgartigimod alfa-fcab.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.

Serious side effects of efgartigimod alfa

Along with its needed effects, efgartigimod alfa may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor or nurse immediately if any of the following side effects occur while taking efgartigimod alfa:

Other side effects of efgartigimod alfa

Some side effects of efgartigimod alfa may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

For healthcare professionals

Applies to efgartigimod alfa: intravenous solution.

General adverse events

The most common adverse reactions reported have included respiratory tract infections, headaches, and urinary tract infections.^[Ref]

Respiratory

• Very common (10% or more): Respiratory tract infections (33%)

In clinical trials, 33% of patients treated with this drug experienced respiratory tract infections compared to 29% of placebo patients.

Nervous system

• Very common (10% or more): Headache (32%; included migraine, procedural headache)
• Common (1% to 10%): Paraesthesia (included oral hypoesthesia, hypoesthesia, hyperesthesia)

Immunologic

• Very common (10% or more): Drug antibodies (20%)
• Common (1% to 10%): Neutralizing antibodies

Hematologic

• Very common (10% or more): Below normal WBC counts (12%), below normal lymphocytes (28%), and below normal neutrophils (13%)

Below normal levels of WBCs, lymphocytes, and neutrophils were observed in patients treated with this drug (12%, 28%, and 13%, respectively) compared with placebo (5%, 19%, and 6%, respectively).

Genitourinary

• Very common (10% or more): Urinary tract infections (UTI; 10%)

In clinical trials, 10% of patients treated with this drug experienced UTI compared to 5% of placebo patients.

Hypersensitivity

• Frequency not reported: Hypersensitivity reactions including rash, angioedema, and dyspnea

Musculoskeletal

• Common (1% to 10%): Myalgia

See also:

Further information

Efgartigimod alfa side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.

Medical Disclaimer