What Are the Common Side Effects of Immunotherapy in People With Metastatic Bladder Cancer?

If you have metastatic bladder cancer, your doctor might recommend immunotherapy. Immunotherapy drugs called immune checkpoint inhibitors (ICIs) help your immune system attack cancer cells. These medicines target “checkpoint” proteins. When those proteins are blocked, your immune system can kill cancer cells and stop or slow down tumor growth. Immunotherapy can be a helpful treatment for advanced bladder cancer. But these treatments come with side effects that could be mild or serious. 

Immune checkpoint inhibitors (ICIs) and antibody-drug conjugates (ADCs), another type of immunotherapy drug, can cause fatigue. It’s more than normal tiredness. You might feel like you don’t have any energy and get worn out very easily. This kind of exhaustion can make it hard to think clearly. Sleep might not relieve the feeling completely. Your body could feel weak or heavy. To manage fatigue, your doctor may recommend supplements or medicines. Take note of when your energy is highest, and schedule your most important tasks during those times. Eat well and try to move your body when you can. 

Any of the immunotherapy medications used for advanced bladder cancer can upset your digestion. If you have diarrhea, take care that you don’t become dehydrated. If the diarrhea gets worse or won’t go away, your doctor can give you medicine to help so you can stay on your immunotherapy. If you’re constipated, drink lots of fluids, eat small meals, and prioritize high-fiber foods. Ask your doctor about stool softeners, laxatives, or enemas. 

Rash is a common side effect of both ICIs and ADCs. If you get a rash, it may be itchy, red or discolored, and dry. You could also get psoriasis. These skin problems usually develop early in your immunotherapy treatment, days to months after you start. Some people have a reaction where the medication needle was inserted, like swelling, soreness, or itchiness. Use a fragrance-free cream to keep your skin moisturized. Stay out of the sun. Your doctor can recommend treatment for skin irritation, such as topical creams or oral medications. 

Immunotherapy drugs can cause fever, chills, weakness, aches, headache, and trouble breathing. These flu-like symptoms can be a normal side effect, but they could also be signs of infection. Tell your doctor if you: 

• Have a fever over 100.4 F
• Have chills
• Develop a cough
• Have a sore throat

ICIs sometimes interfere with hormone-making glands. These drugs change how your immune system works, and sometimes it can attack other parts of your body, like your endocrine system. That can cause complications like thyroid dysfunction and hypophysitis, an inflammation of your pituitary gland.

Some symptoms are: 

• Vision changes
• Extreme weakness
• Unusual headaches 
• Weight loss or weight gain
• Extreme or low hunger
• Deepening voice

If you have endocrine problems, your doctor will check your thyroid, adjust your treatment, and prescribe medication to balance your hormones. 

ICIs and ADCs can make you queasy. Nausea is a common side effect of immunotherapy, but your doctor can give you medication to take before you start your treatment to prevent it. There are many options, so your doctor will recommend the best ones for you. To fight nausea, drink water and clear fluids, like broth, throughout the day. Try cold foods like Popsicles or pudding, or starchy ones like toast and rice. Practice relaxation techniques or ask your doctor about acupuncture. 

You may find you’ve lost your appetite while being treated with ICIs. And that might not be the only change when it comes to eating. You could also have dry mouth, be unable to taste as well, or even taste things differently — especially bitter and sweet foods. If you’re having trouble eating, try drinking a nutrition shake. Eating small portions throughout the day can help. For dry mouth, you can chew gum, avoid caffeine and ask your doctor about over-the-counter remedies. Try to cope with taste changes by drinking lots of fluids, brushing and flossing your teeth regularly, and using flavor-masking ingredients like citrus and pickles. 

This nerve damage causes numbness or pain in your hands and feet. Peripheral neuropathy is a common side effect of ADCs, including enfortumab vedotin (Padcev). It can impact other parts of your body, too, since it affects the nerves outside your brain and spinal cord.

Your doctor can change your dose of ADC medication to help with your peripheral neuropathy. They may recommend vitamins or other medications to ease your symptoms. Exercise and physical and occupational therapy can improve your peripheral neuropathy.  

In some cases, immunotherapy can cause major side effects. ADCs can cause lung inflammation as well as very high blood sugar. Your doctor should monitor your blood sugar levels. Let them know if you notice you’re extra thirsty or peeing more often. Infusion reactions from ICIs are like allergic reactions you have when getting your medicine. Tell someone right away if you have itchy skin, rash, fever, chills, dizziness, or trouble breathing. ICIs can also cause serious inflammation in your lungs, colon, kidneys, liver, pancreas, or other organs.

Watch out for: 

• Changes in urination, including blood in your urine
• Yellowish skin or eyes 
• Shortness of breath or bad cough
• Stomach pain
• Black or bloody stools

Tell your doctor right away about any side effects you have during or after immunotherapy treatment. It’s important to take care of any issues right away to avoid serious problems. Your doctor could stop or change your treatment, adjust your dose, or prescribe extra medicines to help you feel better. Keep a record of your side effects. Write down the physical and emotional changes you’re experiencing every day. It will make it easier to tell your doctor what’s been going on and remember questions for your appointments. You can use an app, a handout from your doctor, or just a notebook.