See also How to Use section.
Fatigue or dizziness may occur. If either of these effects lasts or gets worse, tell your doctor or pharmacist promptly.
People using this medication may have serious side effects. However, your doctor has prescribed this drug because he or she has judged that the benefit to you is greater than the risk of side effects. Careful monitoring by your doctor may decrease your risk.
Tell your doctor right away if you have any serious side effects, including: signs of infection (such as fever, runny/stuffy nose, new/worsening cough), diarrhea with blood/mucus, mouth/throat sores, severe stomach/abdominal pain, symptoms of liver disease (such as nausea/vomiting that doesn't stop, loss of appetite, yellowing eyes/skin, dark urine), signs of kidney problems (such as change in the amount of urine, pink/bloody urine), easy bruising/bleeding, swelling hands/ankles/feet, unusual weakness, joint stiffness/pain, muscle weakness/pain, eye redness/pain, sensitivity to light, vision changes.
Avelumab may cause hormone gland problems (such as thyroid, pituitary, adrenal, pancreas). Your body could make too much or too little hormone. Tell your doctor right away if you have any symptoms such as: cold or heat intolerance, unexplained weight loss/gain, increased thirst/urination, mood or behavior changes (such as decreased sex drive, irritability, forgetfulness), slow/fast/pounding/irregular heartbeat, unusual tiredness, constipation.
Get medical help right away if you have any very serious side effects, including: chest pain, shortness of breath.
Avelumab can commonly cause itching or a rash that is usually not serious. However, you may not be able to tell it apart from a rare rash that could be a sign of a severe reaction. Get medical help right away if you develop any rash or itching.
A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.
This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.
In the US - Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.
In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.