1. Immune checkpoint inhibitors
The most progress in immunotherapy for lung cancer has been made in immune checkpoint inhibitors. Immune checkpoints are molecules on the immune cells that can start or stop an immune response. The immune system uses these molecules to help determine what is normal and what should be attacked. Cancer cells sometimes trick these checkpoints to stop the body from attacking them. Drugs can target these checkpoints and help them respond against cancer cells.
There are several drugs that target immune checkpoints that are approved for treatment of lung cancer. Many of these drugs block or "inhibit" the contact between the PD-L1 protein and the PD-1 receptor on the T cell. The PD-L1/PD-1 interaction functions as a brake that prevents the immune system from responding to cancer. By blocking this interaction, the immune system is able to recognize and attack cancer cells. One of these approved drugs targets another immune checkpoint called CTLA4. When CTLA4 is blocked, the body is able to ramp up the number of immune cells that are available to respond against cancer cells.
Checkpoint inhibitors are given as an intravenous (IV) infusion. These drugs can have similar side effects to chemotherapy, including fatigue, nausea, itching, skin rash, and more, but they are generally less toxic than chemotherapy. However, because the drugs work by stimulating the immune system, it is possible to develop serious immune-related side effects from an over-stimulated immune system that can affect how your organs function. It is important to work with your care team to help monitor all side effects.
2. Cancer vaccines
When most people think of vaccines they think of treatments that prevent disease. However, there is another type of vaccine called a therapeutic vaccine. This type of vaccine treats an existing cancer by making the immune system better at killing cancer cells. These vaccines target proteins that are present in cancer cells that are either not present in normal cells or are only sparingly present in normal cells. Sometimes, the vaccines are customized to target proteins that are unique to an individual’s cancer. In other cases, the vaccines target cancer-specific proteins shared by many people. Before a vaccine is given, it is often necessary to first take a medicine to dampen the types of immune cells that may allow a cancer to grow and boost the types of immune cells that can respond to cancer. Right now, these vaccines are being studied in clinical trials. There is currently no FDA-approved vaccine for lung cancer treatment.
3. Adoptive T cell therapy
In this therapy, T cells (a type of white blood cell in the immune system) are removed from your body and then altered in a laboratory so they are better at attacking your specific cancer cells. Finally, the enhanced T cells are put back into your body to help it fight cancer. Removing the T cells from your body requires a procedure called plasmapheresis which helps filter your blood to specifically identify certain types of blood cells. Right now, this type of therapy is being studied in clinical trials and no such treatment is FDA approved for treating lung cancer.