Side Effects of Immunotherapy

Approved by the Cancer.Net Editorial Board, 05/2019

Immunotherapy, also called biologic therapy, is a type of cancer treatment that boosts the body's natural defenses to fight cancer. It uses substances made by the body or in a laboratory to improve, target, or restore immune system function.

Your doctor may recommend immunotherapy as the only treatment. Or it may be given after or at the same time as another treatment, such as chemotherapy, radiation therapy, or surgery. Read more about the different types of immunotherapy.

Why immunotherapy causes side effects

Certain types of immunotherapy attack cancer or slow its spread to other parts of the body. Others make it easier for the immune system to destroy cancer cells.

Immunotherapy sometimes results in the immune system attacking healthy cells, which can cause side effects.

Managing side effects

Different types of immunotherapy can cause different side effects. Many side effects depend on the type of treatment, the type and location of the cancer, and a person’s general health. Before your immunotherapy begins, talk with your doctor about the possible side effects of your specific treatment.

Your health care team can help you prevent or treat many side effects. This is called palliative care or supportive care and is an important part of cancer treatment. Let the health care team know about any new or worsening medical problems you have as soon as possible, even if you do not think it is serious or related to the immunotherapy.

Side effects of immunotherapy can be mild, moderate, or even life-threatening. Depending on how severe your side effects are, your doctor may pause the treatment or prescribe a type of medication called a corticosteroid. If side effects worsen or do not improve, your doctor may stop immunotherapy.

If you receive medical care at an emergency room or other place not familiar with your cancer treatment, be sure to tell the health care team there that you are receiving immunotherapy. If possible, provide the name of the specific drug(s), your oncologist, and/or the cancer center where you receive immunotherapy. Keeping this information written on paper and stored in your wallet can be helpful in case you need it quickly. Talk with your cancer care team about which details of your treatment you should carry with you.

Common immunotherapy side effects

The most common side effects of immunotherapy include:

Skin reactions. Skin redness, blistering, and dryness are common reactions to immunotherapy. Skin on the fingertips may crack. Skin may also become more sensitive to sunlight. A lot of scratching can break the skin, making it more prone to infections. Inflammation around the nails can make grooming, dressing, and other activities painful or difficult. Read more about managing and treating skin irritations and reactions.

Flu-like symptoms. Fatigue (feeling tired), fever, chills, weakness, nausea (feeling sick to your stomach), vomiting (throwing up), dizziness, body aches, and high or low blood pressure are all possible side effects of immunotherapy.

They are especially common in non-specific immunotherapy and oncolytic virus therapy. It is very important to stay hydrated when experiencing these symptoms. Seek medical attention if you are unable to keep any liquids down, and talk with your doctor about how to manage these side effects. Many side effects will go away on their own, but others can be very serious and require attention right away.

Other possible side effects you may experience include:

  • Muscle aches

  • Shortness of breath (trouble breathing)

  • Swelling of legs (edema)

  • Sinus congestion

  • Headaches

  • Weight gain from retaining fluid

  • Diarrhea

  • Hormone changes, including hypothyroidism, which is when the thyroid gland does not make enough thyroid hormones and can cause fatigue and weight gain

  • Cough

It is important to note that there can be other side effects that are not listed here. Talk with your health care team about what side effects you can expect, who to contact, and what to do if you have unexpected side effects. Learn more about managing physical side effects.

Follow-up care

Getting care for side effects after treatment ends is important. Many side effects will go away when treatment ends, but some effects can last beyond the treatment period. Other effects may appear months or years later. Your health care team can help you manage long-term side effects.

The information in this article is based on ASCO recommendations on managing immunotherapy related side effects.

Related Resources

What You Need to Know About Immunotherapy Side Effects

What It’s Like Taking Immunotherapy to Treat Cancer

Tumor-Agnostic Treatment for Cancer: An Expert Perspective

More Information

National Cancer Institute: Immunotherapy to Treat Cancer

National Comprehensive Cancer Network: Understanding Immunotherapy Side Effects (PDF)

ASCO answers; Side Effects of Immunotherapy

Download ASCO's free 1-page (front and back) fact sheet on Side Effects of Immunotherapy. This printable PDF provides an overview of side effects which may arise from immunotherapy, and how they are treated. The back side includes a symptom tracker for you to fill out with your health care team. Order printed copies of this fact sheet from the ASCO Store.