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side effects

Like any medication, immunotherapies may cause side effects. Although some effects are more common with certain medications, each person's experience may be different. Not everyone experiences all side effects. It's important to talk with your doctor about possible treatment side effects and options for minimizing or eliminating some of them. 

Report all symptoms or changes in your health to your doctor. You may also report any suspected side effects directly to the online or by calling: 1-800-FDA-1088. This table lists some of the most common and the most serious side effects associated with different types of treatment. This is not a complete list.

Below are some of the side effects seen with immunotherapies:

Side effects may vary depending on your general health, the type of agent and dose you are on, other medications you take, the site of your cancer and other factors. It's important that you report any symptoms or changes in your health status to your doctor.  Some of these effects may improve with medication or other medical interventions.

Allergic reactions

Any therapy can cause an allergic reaction in someone who is sensitive to the medication. Allergic reactions may range from mild to severe. Rarely these reactions can be fatal. Your oncologist may prescribe medication to decrease your risk for severe allergic reactions caused by

Anemia, bleeding and low white blood cell counts

Some immunotherapies, especially monoclonal antibodies, damage bone marrow, where blood cells are made. This can result in too few red blood cells (anemia), too few platelets (thrombocytopenia) and a low white blood cell count (neutropenia).These bone marrow effects can lead to symptoms like fatigue, rapid heart rate, bleeding and increased risk for infection. Most of the time, these changes are mild. Your oncologist may test your blood, to make sure that your blood counts do not drop too low, which could delay treatment. 

Birth defects

Many immunotherapies can cause birth defects. Women are cautioned not to become pregnant while on . It's important to speak with your doctor about your plans for pregnancy before starting treatment. 


Fatigue may be caused by cancer or treatments, including immunotherapies. You should report fatigue to you doctors so they can check and treat you for underlying causes, including depression, sleep disturbances and medication side effects. You may be able to improve your energy level with these suggestions: 

  • making sure that your diet is balanced and provides you with adequate nutrition. Ask your doctor for a referral to a nutritionist if you need help figuring out your nutritional needs.
  • making sure that you get adequate sleep. 
  • trying to stay physically active, which can help improve your energy level. 

Heart damage

Certain targeted therapiesespecially anti-Her2 therapiescan cause heart damage. Your oncologist may run tests to make sure that your heart function is normal before, during and after treatment. Some drugs may help protect the heart from damage caused by targeted. Heart damage caused by treatment can also be minimized by lowering the dose, changing how it is given or switching to different drug.  

Immune-mediated effects

Immune-mediated (also known as auto-immune) side effects happen when the immune system attacks normal cells. These side effects are most likely with checkpoint inhibitors and may be severe or even life-threatening. Although these effects may be reversible, some can be severe. Symptoms depend on the organs that are attacked. Some of the more common organs that may be affected include: 

  • colon
  • kidneys
  • liver
  • lungs
  • adrenal glands
  • pancreas (leading to diabetes)
  • pituitary gland
  • skin
  • thyroid

Steroid medications are most commonly used to treat immune-mediated effects of checkpoint inhibitors. Your oncologist may temporarily or permanently discontinue treatment or lower your dose, depending on the severity of the effects. 

Joint or muscle pain

Certain targeted therapies may cause joint or muscle pain. Exercise, yoga, and acupuncture may help relieve joint pain. Ask your doctor about whether you can take nonsteroidal anti-inflammatories or other medication to improve joint pain caused by these therapies.

Mouth and tongue sores

Some targeted therapies can cause painful sores of the mouth and lips (called stomatitis), which can make eating painful. Certain medications and mouthwashes can help to repair mouth cells, coat the sores or block the pain caused by the sores. Rinsing your mouth with salt or baking soda can also improve mouth sores. 

Nausea, vomiting and appetite changes

Several different medications help to reduce nausea during treatment. This can improve appetite, reduce weight loss and support a balanced diet—referral to a nutritionist can help assure that you maintain a balanced diet during treatment. Certain foods may be more or less likely to trigger nausea, vomiting or upset stomach. 


Some immunotherapies, especially monoclonal antibody drugs, can cause rashes. Rashes may range from mild to severe, depending on the agent.  

Table of common and serious side effects of different types of 

Report all symptoms or changes in your health to your doctor. You may also report any suspected side effects directly to the online or by calling: 1-800-FDA-1088. This is not a complete list of possible side effects.

Type of agent Names of agents Common side effects Serious side effects
Immune checkpoint inhibitor

Keytruda (pembrolizumab) 
Tecentriq (atezolizumab) 
Opdivo (nivolumab) 
Imfinzi (durvalumab)
Yervoy (ipilumumab) 

Cough, fatigue, diarrhea, nausea, decreased appetite, vomiting and stomach pain, musculoskeletal pain, rash, shortness of breath

Severe immune-mediated side effects that may affect the colon, kidneys, liver, lungs, adrenal glands, pancreas (leading to diabetes), pituitary gland, skin, thyroid

Anti-Her2 antibody

Herceptin (trastuzumab)
&  biosimilars (e.g.,Trazimera)

Kadcyla (trastuzumab emtansine)
Perjeta (pertuzumab)
Phesgo (pertuzumab, trastuzumab, and hyaluronidase-zzxf)

Allergic reactions, constipation, diarrhea, fatigue or weakness, fever and chills, hairloss, joint and muscle pain, low blood counts, mouth sores, nausea, neuropathy, rash, vomiting, Heart disease, severe allergic reaction
Anti-EGFR antibody Erbitux (cetuximab) Headache, nausea, diarrhea, rash and itching, fingernail and toenail changes, low blood counts, mouth sores, weakness   Severe or fatal allergic reactions, heart attacks, lung disease
Anti-EGFR antibody Vectibix (panitumumab)

Used alone: skin rash, infections at the side of the fingernails or toenails, fatigue, nausea, diarrhea

When combined with chemotherapy: abnormal levels of magnesium, calcium and potassium; weakness; nausea; loss of appetite; diarrhea; skin rash; mouth sores

Severe skin reactions, serious allergic reaction
Antibody-drug conjugate  Trodelvy (sacituzumab govitecan-hziy) Nausea, low white blood count, constipation, diarrhea, fatigue, anemia, decreased appetite, stomach pain, vomiting, hair loss, rash Severe low white blood counts, severe diarrhea, severe allergic reaction
Anti-VEGF or  VEGF receptor antibody

Avastin (bevacizumab)  Zirabev (bevacizumab) 
Cyramza (ramucirumab)

Nose bleeds, headache, high blood pressure, nasal symptoms, too much protein in the urine, taste changes, dry skin, back pain, watery eyes, skin rashes

Very high blood pressure, heart problems, stomach or intestinal tears, fistula (abnormal connection between organs), nonhealing wounds, swelling of the brain

Intron A (Interferon alfa-2b)
Sylatron (peginterferon alfa-2b)

Chills; fever; fatigue; confusion; headache; dizziness; muscle and joint pain; decreased appetite, nausea, vomiting or diarrhea; low blood pressure, rash

Abnormal heartbeat, chest pain and other heart problems, depression or other changes in mental status, damage to vision, thyroid abnormalities, diabetes, liver damage
Nonspecific Proleukin (aldesleukin) Low blood pressure, diarrhea, nausea, vomiting, chills, kidney problems, shortness of breath, rash, abnormal liver or kidney measures in blood, confusion, low platelet counts Severe low blood pressure, heart problems, infection, kidney damage, changes in mental status, worsening of pre-existing immune-mediated conditions
Cancer vaccine Imlygic (talimogene laherparepvec)

Tiredness, chills, fever, nausea, flu-like symptoms, pain at treatment site

Accidental exposure may lead to transmission of herpes virus to other areas of body and can be infectious to other people 
Cancer vaccine Provenge (sipuleucel-T) Chills, fatigue, fever, back pain, nausea, joint ache, headache Severe allergic reaction