Our immune system is made up of a network of organs and cells that protect the body from foreign invaders, including cancer cells. When our immune system identifies foreign cells, such as cancer, it attacks and destroys them.

Immune checkpoint inhibitors (ICI) play an integral role in our bodies’ defense system against cancer.  To understand how immune checkpoint inhibitors work, we breakdown the role of these drugs:

• ICIs help prevent our immune system from “overreacting” and attacking the healthy cells in our body. 

• A specific type of cell in our immune system, called T cells, have “checkpoint” proteins which allow them to identify cancerous cells and initiate an immune response. 

• When our bodies begin to attack cancer cells, the immune system monitors the response to prevent damage to healthy tissue using additional “checkpoint” proteins.  

• Certain cancer cells can create these “checkpoint” proteins preventing T cells from launching an attack. 

How ICI Therapy Works

• ICIs stop cancer cell proteins from preventing a T cell initiated immune response. 

• T cells are then able to continue identifying the cancer cells as “bad” and destroy them. 

• Immune checkpoint inhibitor treatment doesn’t attack cancer cells directly. Instead, they work by better equipping the immune system to identify and destroy cancer cells. 

Types of ICI Therapy 

As of December 2022, there are ten FDA-approved medications blocking four types of immune checkpoints in the human body. 

• PD-1 Inhibitors 

  • Cemiplimab 

  • Dostarlimab 

  • Nivolumab 

  • Pembrolizumab 

• PD-L1 Inhibitors 

  • Atezolizumab 

  • Avelumab 

  • Durvalumab 

• CTLA-4 Inhibitors 

  • Ipilimumab 

  • Tremelimumab 

• LAG-3 Inhibitors 

  • Relatlimab

Cancers are Treated with ICI Therapy

ICIs have been approved to treat a wide variety of cancers at various stages of disease. Each drug is approved for a specific type of cancer.

Some of the more common cancers treated with these medications include: 

• Breast cancer 

• Lung cancer 

• Gastric cancer 

• Cervical cancer 

• Melanoma  

Common Side Effects of ICI Therapy

ICI therapy may have side effects that manifest themselves in a variety of ways. While it is impossible to know if they will occur, it is important to be aware of the signs and symptoms so you can contact your oncology team.

Some common side effects with therapy include: 

• Rash 

• Diarrhea

• Fatigue

• Respiratory symptoms such as difficulty breathing, cough, and shortness of breath 

• Endocrine disorders such as hypo or hyperthyroidism

Pro Tip

Talk to your oncology team about who to contact for any side effects prior to starting treatment. Our Iris Nursing staff is available 24/7 for those moments in between appointments with your oncologist when you may have questions or need help. We are available via phone call or messaging to help address any needs you may have. 

Questions to Ask Your Doctor

• Am I a candidate for immune checkpoint inhibitor therapy? 

• What side effects should I expect from my specific treatment plan? 

• How often will I be receiving this medication? 

• Are there any additional precautions I should be aware of?