The immune system ›protects the human body from viral and bacterial infections and cancer. However, cancer cells have the ability to hide from the immune system so they can continue to grow and form tumors. Immunotherapy is a newer approach to cancer treatment designed to help the immune system recognize, attack, and kill these cancer cells.

Several types of immunotherapy used to treat lung cancer are made of monoclonal antibodies, which are immune proteins made in a lab. These antibodies are bioengineered to target a specific type of protein called an antigen. Because immunotherapies can target cancer while avoiding healthy cells, they can be useful in treating lung cancer.

Here are the main types of immunotherapy currently being used — or under development — to treat lung cancer.

1. PD-1/PD-L1 Inhibitors

In the human body, immune responses are switched on and off via checkpoint proteins found on different immune cells. Checkpoint proteins act like switches to turn an immune response, such as inflammation, on or off.

One immune checkpoint system is known as the PD-1/PD-L1 checkpoint. The protein PD-1 is found on the surface of immune cells known as T cells, which can attack and destroy cancer cells. Tumor cells that produce the PD-L1 protein can stop the immune system from attacking them.

Immune checkpoint inhibitors (ICIs) are drugs that prevent cancer cells from using checkpoint proteins to switch off the immune response. This keeps the T cells and immune system activated. As a result, the immune system attacks the tumor cells and the tumors shrink over time.

Types of PD-1 and PD-L1 Inhibitors

The U.S. Food and Drug Administration (FDA) has approved four PD-1/PD-L1 inhibitors to treat advanced non-small cell lung cancer (NSCLC):

• Pembrolizumab (Keytruda)
• Cemiplimab-rwlc (Libtayo)
• Nivolumab (Opdivo)
• Atezolizumab (Tecentriq)

The FDA has also approved a PD-L1 inhibitor called durvalumab (Imfinzi) for treating both advanced small cell lung cancer (SCLC) and NSCLC.

When Are PD-1 and PD-L1 Inhibitors Used?

Immune checkpoint inhibitors can be used to treat different cases of NSCLC and SCLC. Some examples of PD-1 and PD-L1 Inhibitors include the following:

• Pembrolizumab and cemiplimab-rwlc are given to people with stage 3 NSCLC who cannot have radiation therapy or chemotherapy.
• Pembrolizumab, cemiplimab-rwlc, or atezolizumab is given as a first-line treatment (in combination with chemotherapy) to some people with advanced NSCLC.
• Pembrolizumab, nivolumab, and atezolizumab are used in certain cases of advanced NSCLC.
• Durvalumab is used to treat stage 3 NSCLC that cannot be removed with surgery and that has not progressed after treatment with chemotherapy and radiation.
• Durvalumab and atezolizumab are used as first-line treatments for advanced SCLC in combination with platinum-based chemotherapy.

2. CTLA-4 Inhibitors

CTLA-4 is another checkpoint used by the immune system to control the activity of T cells. FDA-approved CTLA-4 Inhibitors for lung cancer include:

• Ipilimumab (Yervoy) in combination with nivolumab and chemotherapy as a first-line treatment for those with advanced NSCLC
• Tremelimumab-actl (Imjudo) along with durvalumab to treat metastatic NSCLC when cancer cells lack certain mutations

3. Lung Cancer Vaccines

Researchers are currently working to develop vaccines that can prevent and treat lung cancer. Vaccines are another type of immunotherapy. Cancer vaccines can work in different ways, but all of them work by training the immune system to identify and remember a specific antigen, or protein target, found on cancer cells. After receiving the vaccine, the immune system will “remember” the antigen and attack and destroy any cancer cells that have it.

While cancer vaccines aren’t yet available as lung cancer treatment, some people can access them by participating in oncology clinical trials.

4. CAR T-Cell Therapy

Chimeric antigen receptor (CAR) T-cell therapies work by engineering your own T cells to recognize your lung cancer. First, T cells are harvested from tissue resected (removed) during lung cancer surgery. Then large numbers of your bioengineered T cells are produced in a lab before being infused back into your body. These T cells will then attack and kill cancer cells, causing tumors to shrink.

CAR T-cell therapies have been used to treat blood cancers like leukemia and lymphoma for years and are now being developed for some solid cancers. They’re currently under development in clinical trials for lung cancer. If you’re curious about lung cancer immunotherapy and whether it might be an option for treating your cancer, talk to your oncologist.

What Are the Side Effects of Immunotherapy?

Immunotherapy and ICIs work to activate your immune system, and they can cause many common side effects that are similar to flu-like symptoms. Side effects include:

• Fever
• Nausea
• Fatigue
• Loss of appetite
• Itching or skin rash
• Joint pain
• Diarrhea
• Headache
• High or low blood pressure

Infusion Reactions

Immunotherapy drugs are typically given intravenously (by injection into a vein), which can lead to an infusion reaction. Infusion reactions look and feel similar to an allergic reaction and can include symptoms such as:

• Fever
• Chills
• Itchy skin
• Flushing in the face
• Rash
• Wheezing or trouble breathing
• Dizziness

If you begin experiencing any of these symptoms during an infusion, let your doctor or nurse know immediately.

Autoimmune Reactions

In some cases, immunotherapy can over-activate the immune system and cause it to start attacking healthy tissues in other parts of the body, including the intestines, liver, lungs, kidneys, and other organs. If you begin having autoimmune reactions, your doctor may adjust your medication or prescribe other medications to address the reaction.

Read more about specific medications in this list of treatments for lung cancer.

Talk With Others Who Understand

MyLungCancerTeam is the social network for people with lung cancer and their loved ones. On MyLungCancerTeam, more than 12,000 members come together to ask questions, give advice, and share their stories with others who understand life with lung cancer.

Are you taking immunotherapy for lung cancer? Share your experience in the comments below, or start a conversation by posting to your Activities feed.