Immunotherapy side effects: What to know

If you’ve researched cancer treatment options, you’ve probably heard of immunotherapy, which trains the immune system to attack cancer, rather than attacking the cancer directly. You also might have heard that immunotherapy doesn’t have side effects. But that’s not always the case. “With the most common type of immunotherapy — immune checkpoint therapies — about 5-10% of patients experience side effects, and they’re life-threatening in about 1-2% of those cases,” says Vivek Subbiah, M.D. Examples of immune checkpoint drugs include: pembrolizumab (Keytruda), nivolumab (Opdivo), atezolizumab (Tecentriq), ipilimumab (Yervoy), avelumab (Bavencio) and durvalumab (Imfinzi). Immunotherapy side effects often differ from those commonly seen with other types of cancer treatment. Here’s what patients should know. Fatigue, inflammation top common side effects “As with many cancer therapies, fatigue tends to be one of the most common,” says Van Morris, M.D. But immunotherapy drugs also can cause inflammation throughout the body. For example, patients may experience skin inflammation as pigment changes, a rash and feeling itchy, sometimes even without a rash. Inflammation in the lungs can cause a cough and chest pains. The colon may also become inflamed, causing abdominal pain and diarrhea. One of the rarer but more concerning side effects is hypophysitis – inflammation of the pituitary gland. “The biggest challenge is that it manifests in so many ways and can only be definitively determined with blood work,” says Sumit Subudhi, M.D., Ph.D. “But the patient may experience fatigue, fever or a headache.” We don’t know for sure which immunotherapy patients are more likely to experience these side effects. “But side effects don’t tend to be related to the cancer type,”...