What Are the Side Effects of Immunotherapy?

Immunotherapy helps the body’s immune system fight kidney cancer, but it can also cause side effects when the immune system mistakenly attacks healthy tissues. While many people tolerate treatment well, others may experience mild to severe immune-related side effects that require close monitoring and timely management.

Common Side Effects

These are often mild and manageable:

• Fatigue – Feeling unusually tired is one of the most common symptoms.
• Skin rash or itching – May appear during the first few weeks of treatment.
• Diarrhea or colitis – Inflammation of the colon may cause frequent bowel movements, cramps, or bleeding.
• Nausea or loss of appetite – Can affect food intake and weight.
• Low-grade fever – A sign that the immune system is activated.

Less Common but More Serious Side Effects

These happen when the immune system starts attacking normal organs:

• Pneumonitis – Inflammation of the lungs, leading to cough and shortness of breath.
• Hepatitis – Liver inflammation causing yellowing of the skin (jaundice) or abnormal liver tests.
• Endocrine issues – Inflammation of glands like the thyroid or adrenal glands, leading to hormone imbalances, weight changes, or fatigue.
• Kidney inflammation (nephritis) – May cause changes in kidney function and need dose adjustments.

When to Contact a Doctor

Any new or worsening symptoms should be reported immediately. While mild symptoms can often be managed with medication, more serious effects may require:

• Steroids (e.g., prednisone) to reduce inflammation
• Pausing or stopping immunotherapy
• Hospital care in rare, severe cases

Good to Know

Not everyone experiences side effects. Some people feel well throughout treatment, while others need supportive care. The key is early recognition and communication with your care team.

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