Immunotherapy is the use of drugs to stimulate a person’s own immune system so it can better recognize and destroy cancer cells.
Immune checkpoint inhibitors
An important part of the immune system is its ability to keep itself from attacking normal cells in the body. To do this, it uses “checkpoints,” which are proteins on immune cells that need to be turned on (or off) to start an immune response. Cancer cells sometimes use these checkpoints to keep from being attacked by the immune system.
Newer drugs that target these checkpoint proteins, called checkpoint inhibitors, can help restore the immune response against the cancer cells.
Pembrolizumab (Keytruda) and nivolumab (Opdivo) are drugs that target PD-1, a protein on immune system cells called T cells. PD-1 helps keep the T cells from attacking other cells in the body. By blocking PD-1, these drugs boost the immune response against cancer cells. This can shrink some tumors or slow their growth.
Either of these drugs can be used in people whose mesothelioma is still growing after initial treatment. Nivolumab can also be used along with another checkpoint inhibitor, ipilimumab (see below), as the first treatment in people with mesothelioma that cannot be removed with surgery.
These drugs are given as an intravenous (IV) infusion every 2 to 6 weeks.
Ipilimumab (Yervoy) is another drug that boosts the immune response, but it has a different target. It blocks CTLA-4, another protein on T cells that normally helps keep them in check.
This drug can be used along with nivolumab (see above) to treat advanced mesothelioma, but it’s not used alone.
It's given as an intravenous (IV) infusion, usually once every 6 weeks.
Side effects of checkpoint inhibitors
Side effects of these drugs can include fatigue, cough, nausea, itching, skin rash, decreased appetite, constipation, joint pain, and diarrhea.
Other, more serious side effects occur less often:
Infusion reactions: Some people might have an infusion reaction while getting these drugs. This is like an allergic reaction, and can include fever, chills, flushing of the face, rash, itchy skin, feeling dizzy, wheezing, and trouble breathing. It’s important to tell your doctor or nurse right away if you have any of these symptoms while getting one of these drugs.
Autoimmune reactions: These drugs work by removing one of the safeguards from the body’s immune system. Sometimes the immune system then starts attacking other parts of the body, which can cause serious or even life-threatening problems in the lungs, intestines, liver, hormone-making glands, kidneys, or other organs. These types of side effects seem to happen more often with ipilimumab than with the PD-1 inhibitors.
It’s very important to report any new side effects during or after treatment with any of these drugs to your health care team right away. If serious side effects do occur, you may need to stop treatment and take high doses of corticosteroids to suppress your immune system.