Avelumab Side Effects

Medically reviewed by Philip Thornton, DipPharm. Last updated on May 4, 2025.

Applies to avelumab: intravenous solution.

Precautions

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

Receiving this medicine while you are pregnant can harm your unborn baby. Use an effective form of birth control to keep from getting pregnant during treatment and for at least 1 month after the last dose. If you think you have become pregnant while receiving the medicine, tell your doctor right away.

This medicine may cause infusion-related reactions, which can be life-threatening and requires immediate medical attention. Tell your doctor right away if you start to have a skin rash, dizziness, trouble breathing, chest tightness, swelling in your face or hands, fever or chills while you are receiving this medicine.

Tell your doctor right away if you have a cough, trouble breathing, chest tightness, or any type of breathing problem with this medicine. These could be symptoms of a serious lung problem.

Check with your doctor right away if you or your child have pain or tenderness in the upper stomach, pale stools, dark urine, a loss of appetite, nausea, unusual tiredness or weakness, or yellow eyes or skin. These could be symptoms of a serious liver problem.

Colitis (swelling of the colon or bowel) may occur with this medicine. Tell your doctor right away if you or your child have stomach pain or tenderness, watery or bloody diarrhea, or a fever after receiving the medicine.

Serious problems with the adrenal, pituitary, or thyroid glands (hormone glands) may occur while you or your child are receiving this medicine. Tell your doctor if you start having continuing or unusual headaches, changes in mood or behavior (eg, being irritable or forgetful), lightheadedness, dizziness, or fainting, unusual sluggishness, or an increase in weight.

This medicine may affect blood sugar levels. If you notice a change in the results of your blood or urine sugar tests or if you have any questions, check with your doctor.

Serious skin reactions (eg, exfoliative dermatitis, Stevens-Johnson syndrome, drug rash with eosinophilia and systemic syndrome (DRESS), or toxic epidermal necrolysis) can occur with this medicine. Check with your doctor right away if you or your child have blistering, peeling, or loosening of the skin, chills, cough, diarrhea, itching, joint or muscle pain, red irritated eyes, red skin lesions, often with a purple center, severe acne or a skin rash, sore throat, sores or ulcers on the skin, mouth, or lips, swollen glands, unusual bleeding or bruising, or unusual tiredness or weakness with this medicine.

Tell your doctor right away if you or your child have bloody or cloudy urine, nausea, vomiting, trouble breathing, swelling of the face, feet, or lower legs, unusual tiredness or weakness, or unusual weight gain. These may be symptoms of serious kidney problems (eg, nephritis, kidney failure).

This medicine may increase your risk for heart problems (eg, heart failure, heart attack). Check with your doctor right away if you have chest pain or tightness, decreased urine output, dilated neck veins, extreme tiredness or weakness, irregular heartbeat, swelling of the face, fingers, feet, or lower legs, trouble breathing, or weight gain.

Call your doctor right away if you have difficulty with breathing, swallowing, or talking, muscle weakness, severe tiredness, or sudden numbness and weakness in the arms or legs. These could be symptoms of a nervous system problem.

Check with your doctor if you have a headache, confusion, seizures, stiff neck, or vomiting while receiving this medicine. These may be symptoms of encephalitis.

Check with your doctor right away if you have a severe headache, drowsiness, confusion, general feeling of illness, or stiff neck or back while receiving this medicine. These may be symptoms of meningitis.

Pancreatitis (swelling of the pancreas) may occur while you are receiving this medicine. Tell your doctor right away if you have sudden and severe stomach pain, chills, constipation, nausea, vomiting, fever, or lightheadedness.

Call your doctor right away if you start to have a cough that would not go away, weight loss, night sweats, fever, chills, painful or difficult urination, or flu-like symptoms, such as a runny or stuffy nose, headache, blurred vision, or feeling generally ill. These may be signs that you have an infection.

Tell your doctor right away if you or your child have a rash, changes in eyesight, severe or persistent muscle or joint pain, or severe muscle weakness after receiving this medicine.

This medicine may increase your risk for possible organ transplant rejection. Talk to your doctor about this risk.

Serious side effects of avelumab

Along with its needed effects, avelumab 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 avelumab:

Other side effects of avelumab

Some side effects of avelumab 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 avelumab: intravenous solution.

Cardiovascular adverse events

• Very common (10% or more): Hypotension (25%), hypertension (13%)
• Uncommon (0.1% to 1%): Myocarditis^[Ref]

Dermatologic

• Very common (10% or more): Urticaria (25%), rash (e.g., maculopapular, erythema, dermatitis bullous) (22%), pruritus (10%)
• Uncommon (0.1% to 1%): Psoriasis, arthritis, exfoliative dermatitis, pemphigoid, Stevens Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN), histiocytic necrotizing lymphadenitis, vasculitis, hypophysitis^[Ref]

Endocrine

• Common (1% to 10%): Immune-mediated thyroid disorders (hypothyroidism/hyperthyroidism)
• Uncommon (0.1% to 1%): Adrenal insufficiency, hypopituitarism, hypophysitis^[Ref]

Gastrointestinal

• Very common (10% or more): Abdominal pain (25%), diarrhea (23%), nausea (22%), constipation (17%)
• Common (1% to 10%): Immune-mediated colitis
• Uncommon (0.1% to 1%): Pancreatitis^[Ref]

Hematologic

• Very common (10% or more): Lymphopenia (49%), anemia (35%), thrombocytopenia (27%)
• Common (1% to 10%): Neutropenia
• Rare (0.01% to 0.1%): Hemolytic anemia^[Ref]

Hepatic

• Very common (10% or more): Increased aspartate aminotransferase (AST) (34%), increased alanine aminotransferase (ALT) (20%)
• Common (1% to 10%): Increased bilirubin
• Uncommon (0.1% to 1%): Immune-mediated hepatitis^[Ref]

Immunologic

• Common (1% to 10%): Immunogenicity^[Ref]

Local

• Very common (10% or more): Anorexia (20%), weight loss (15%), increased lipase (14%)
• Common (1% to 10%): Increased amylase^[Ref]

Metabolic

• Very common (10% or more): Anorexia (20%), weight loss (15%), increased lipase (14%)
• Common (1% to 10%): Increased amylase^[Ref]

Musculoskeletal

• Very common (10% or more): Musculoskeletal pain (32%), back pain (25%), arthralgia (16%)

Common (1% to 10%):

• Uncommon (0.1% to 1%): Myositis, rhabdomyolysis, myasthenia gravis^[Ref]

Nervous system

• Very common (10% or more): Dizziness (14%), headache (10%)
• Uncommon (0.1% to 1%): Guillain-Barre syndrome, demyelination, encephalitis^[Ref]

Respiratory

• Very common (10% or more): Couth (18%), dyspnea (11%)
• Common (1% to 10%): Immune-mediated pneumonitis, wheezing^[Ref]

Renal

• Rare (less than 0.1%): Immune-mediated nephritis^[Ref]

Other

• Very common (10% or more): Fatigue (50%), pyrexia (25%), chills (25%), flushing (25%), peripheral edema (20%)^[Ref]

Ocular

• Uncommon (0.1% to 1%): Uveitis, iritis^[Ref]

See also:

Frequently asked questions

• Who makes Bavencio and where is it made?
• What type of drug is Bavencio?

Further information

Avelumab 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