Checkpoint Inhibitors

October 24, 2024

This page was reviewed under our medical and editorial policy by Alexis Boling, MSN-RN, CNML, director, nursing, Immune Effector Cell & Gene Therapy Program, City of Hope® Cancer Center Duarte

Checkpoint inhibitors are a type of immunotherapy and may be used as a treatment for many cancers. They are also known as immune checkpoint inhibitors.

What Are Checkpoint Inhibitors?

Checkpoint inhibitors are a type of immunotherapy treatment. This treatment is used to help the body’s immune system better recognize and destroy cancer cells. It does this by turning off and on checkpoint proteins, which are signals that control the body’s immune response.

This therapy may be used to treat various cancer types, including:

Types of Checkpoint Inhibitors

There are several types of checkpoint inhibitors. The treatment used will depend on the type of cancer being treated. The most commonly used checkpoint inhibitors include the following.

PD-1 and PD-L1: Both are proteins found in T cells that act as a check to the immune system. PD-1 sometimes binds to another protein, PD-L1, and together this stops the immune system from destroying cancer cells. Blocking either PD-1 or PD-L1 proteins may improve the body’s ability to destroy cancer cells.

PD-1 inhibitor medications include:

  • Opdivo® (nivolumab)
  • Libtayo® (cemiplimab)
  • Keytruda® (pembrolizumab)

PD-L1 inhibitor medications include:

  • Imfinzi® (durvalumab)
  • Bavencio® (avelumab)
  • Tecentriq® (atezolizumab)

CTLA-4: This is another type of protein found on T cells. When CTLA-4 binds with the B7 protein it impedes the immune system’s ability to destroy cancer cells. Blocking CTLA-4 through medication may improve the body’s immune response. 

CTLA-4 inhibitor medications include:

  • Imjudo® (tremelimumab)
  • Yervoy® (ipilimumab)

LAG-3: A checkpoint inhibitor protein, LAG-3 sometimes turns off the immune system’s responses to keep it from overworking. Blocking LAG-3 proteins may improve the body’s cancer response. Opdualag, a combination drug of nivolumab and relatlimab, is often used.

How Are Checkpoint Inhibitor Drugs Administered?

All types of checkpoint inhibitor medication are administered intravenously. This means the drug is infused directly into the bloodstream through a vein.

The infusion takes about 30 to 60 minutes. Some types of medication may be given repeatedly over the course of several weeks.

How Do Checkpoint Inhibitors Work?

Checkpoint inhibitors are designed to improve the immune system’s ability to destroy cancer cells by switching off checkpoints, a type of protein that controls immune responses.

Checkpoint inhibitor drugs are a type of monoclonal antibody. These are laboratory-made proteins that may bind to one specific target in the body, such as a cancer cell.

Checkpoints act as an on-off switch for immune system cells, such as T cells, letting them know when to start or stop an immune response. However, checkpoints may prevent the immune system from acting too strongly. This may stop the body from destroying cancer cells.

Checkpoint inhibitor medication switches off these checkpoints, which boosts the immune system and increases its ability to identify and destroy cancer cells.

Side Effects of Checkpoint Inhibitors

Checkpoint inhibitors may cause side effects in some patients. The side effects may vary, depending on the type of treatment given, but the most common include:

  • Fatigue
  • Skin rashes
  • Diarrhea or constipation
  • Shortness of breath
  • Coughing
  • Nausea or appetite loss
  • Liver problems
  • Pain in the muscles and joints

Rarely, more serious side effects may occur, including an immediate reaction to the infusion or a severe autoimmune reaction. Patients will be closely monitored during and after treatment. They should also let their care team know if they experience any changes to their health during treatment.

Checkpoint Inhibitors at City of Hope

City of Hope researchers are at the leading edge of checkpoint inhibitor research and innovations. Our scientists are constantly evaluating new checkpoint inhibitor therapy options to help reduce side effects and create more powerful cancer treatments.

Learn more about our checkpoint inhibitor research

References
References
  • American Cancer Society (2022, November 17). Immune checkpoint inhibitors and their side effects. 
    https://www.cancer.org/cancer/managing-cancer/treatment-types/immunotherapy/immune-checkpoint-inhibitors.html

  • National Cancer Institute (2022, April 7). Immune checkpoint inhibitors. 
    https://www.cancer.gov/about-cancer/treatment/types/immunotherapy/checkpoint-inhibitors

  • National Cancer Institute, NCI Dictionary of Cancer Terms. PD-1. 
    https://www.cancer.gov/publications/dictionaries/cancer-terms/def/pd-1

  • National Cancer Institute, NCI Dictionary of Cancer Terms. CTLA-4. 
    https://www.cancer.gov/publications/dictionaries/cancer-terms/def/ctla-4

  • National Cancer Institute, NCI Dictionary of Cancer Terms. Anti-LAG-3 monoclonal antibody Sym022. 
    https://www.cancer.gov/publications/dictionaries/cancer-drug/def/anti-lag-3-monoclonal-antibody-sym022

  • Tan S, Day D, Nicholls SJ, Segelov E (2022). Immune checkpoint inhibitor therapy in oncology. JACC CardioOncology. 4(5): 579–597. 
    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9830229/

  • Davies M (2019). PD-1/PD-L1 inhibitors for non–small cell lung cancer: incorporating care step pathways for effective side-effect management. Journal of the Advanced Practitioner in Oncology. 10 (Suppl 1): 21–35. 
    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7522661/

  • National Cancer Institute, NCI Dictionary of Cancer Terms. Monoclonal antibody. 
    https://www.cancer.gov/publications/dictionaries/cancer-terms/def/monoclonal-antibody

  • National Cancer Institute, NCI Dictionary of Cancer Terms. Immune checkpoint inhibitor. 
    https://www.cancer.gov/publications/dictionaries/cancer-terms/def/immune-checkpoint-inhibitor

  • Schneider B, Naidoo J, Santomasso B, et al. (2021, November 1). Management of immune-related adverse events in patients treated with immune checkpoint inhibitor therapy: ASCO guideline update. American Society of Clinical Oncology. 
    https://ascopubs.org/doi/full/10.1200/JCO.21.01440