Kidney cancer is one of the 10 most common cancers in both men and women–and the most common type of kidney cancer is called renal cell carcinoma. If caught and treated early, the prognosis is good. But until recently, doctors had few good options to offer patients whose cancer spread despite treatment. All that is changing. In recent years, a new class of immunotherapy drugs, “checkpoint inhibitors,” was approved to treat certain types of skin and lung cancer. Since then, those drugs have shown promise fighting a lot of different cancers, including renal cell carcinoma. Here’s what you need to know about immunotherapy and renal cell carcinoma. 1. What is immunotherapy? Immunotherapy, put simply, enables the immune system to attack cancer cells. When you get a cold, your body’s immune system attacks (and eventually destroys) the foreign germs that are causing your cough and sniffles. That doesn’t happen when a person develops cancer, because cancer cells are masters of disguise; they use special proteins to convince the immune system that they are normal parts of the body, so the body’s natural defenses leave them alone. Immunotherapy “unmasks” the cancer cells, so the body can attack and destroy them. 2. Has immunotherapy been used to treat advanced renal cell carcinoma in the past? Two types of immunotherapies, called interleukin-2 and interferon-alpha, are man-made proteins that stimulate the immune system. Doctors have used them to treat renal cell carcinoma for at least the last decade, but the drugs don’t help everyone. Only about 10 to 20% of those treated see their cancers shrink, and only some of those people experience remission. These drugs have some serious side effects too, including fluid buildup in the lungs, kidney damage, heart attacks and intestinal bleeding, so they can only be given to people who are healthy enough to withstand the side effects. Now that new types of immunotherapies are emerging, interleukin-2 and interferon-alpha are being used less frequently. 3. How do “checkpoint inhibitors” treat renal cell carcinoma? “Checkpoint inhibitors” essentially cancel the off-switch that cancer cells use to shut down the immune system, so the body can begin attacking the cancer. In November 2015, the U.S. Food and Drug Administration (FDA) approved nivolumab (Opdivo), a checkpoint inhibitor, to treat advanced renal cell carcinoma. Right now, the drug is used to treat people whose cancer has gotten worse despite treatment with other medications. Unlike previous immunotherapy treatments, nivolumab is well-tolerated by most people. The most common side effects include fatigue, nausea, cough, itching, rash, loss of appetite, joint pain, constipation and diarrhea. Nivolumab is given by intravenous (IV) infusion, usually every two weeks. 4. Does immunotherapy help people live longer with renal cell carcinoma? In a head-to-head study that compared nivolumab with everolimus, a medication that is often used to treat people whose kidney cancer has progressed despite treatment, the patients who received the nivolumab lived more than five months longer than patients treated with the other medication. More people responded to immunotherapy treatment too; just over 21% of patients who received nivolumab responded, compared to fewer than 4% of those who received everolimus. Immunotherapy also seems to have a longer-lasting impact. The average sustained response–the amount of time the cancer remained under control–was almost two years for patients who received immunotherapy, versus just over a year for those who responded to everolimus. 5. What’s the future look like for immunotherapies that treat renal cell carcinoma? Other checkpoint inhibitors have been approved to treat skin cancers, lung cancer, and head and neck cancers, and it is likely only a matter of time before new immunotherapy medications are approved to treat renal cell carcinoma. In fact, right now there are a number of clinical trials testing checkpoint inhibitors in people with kidney cancer. Investigators are not only trying to figure out which drugs are effective; they’re also trying to figure out when is the best time to give immunotherapy (before or after other treatments have been tried) and how to determine which patients are most likely to benefit from immunotherapy. If you are interested in learning more about immunotherapy, renal cell carcinoma and clinical trials, talk to your healthcare provider. He or she can give you more information about current trials and help you determine if you’re a good candidate for immunotherapy.