Immunotherapy for Advanced Squamous Cell Carcinomas of the Skin

Immunotherapy is the use of medicines to stimulate a person’s own immune system to recognize and destroy cancer cells more effectively. Some types of immunotherapy can be used to treat people with advanced squamous cell carcinoma (SCC) of the skin, also known as squamous cell skin cancer.

Immune checkpoint inhibitors

Just as it’s important that immune cells in the body get activated to fight infections and cancer, it’s also important that they turn off when they are no longer needed. Checkpoint proteins on immune cells act as brakes to slow down immune cell attacks.

Cancer cells sometimes use these checkpoints to avoid being attacked by the immune system.

Drugs that target checkpoint proteins, called checkpoint inhibitors, can help restore the immune response against the cancer cells.

PD-1 and PD-L1 inhibitors

• Cemiplimab (Libtayo) and pembrolizumab (Keytruda) are drugs that target PD-1, a checkpoint protein on immune cells called T cells.
• Cosibelimab (Unloxcyt) is a drug that targets PD-L1, a protein related to PD-1 that is found on some tumor cells and immune cells.

By blocking either PD-1 or PD-L1, these drugs can boost the immune response against cancer cells.

These drugs are given as an infusion into a vein (IV), typically every 3 to 6 weeks.

When might these drugs be used for squamous cell skin cancer?

• Cemiplimab, pembrolizumab, or cosibelimab can be used to treat people with advanced SCC that can’t be cured with surgery or radiation therapy.
• Cemiplimab might be an option before surgery, known as neoadjuvant therapy, for some higher-risk cancers that would be hard to remove completely. The goal is to shrink the cancer to make surgery easier.
• Cemiplimab might be given as adjuvant therapy after surgery and possibly radiation for some higher-risk cancers, to lower the chances of the cancer coming back.

These drugs haven’t been studied in people with weakened immune systems, such as people who take medicines for autoimmune diseases or who have had an organ transplant, so the balance between benefits and risks in these people isn’t clear.

Possible side effects

Common side effects of checkpoint inhibitors can include:

• Feeling tired
• Diarrhea
• Skin rash
• Nausea
• Constipation
• Bone or joint pain
• Loss of appetite

Other, more serious side effects occur less often.

Infusion reactions: Some people might have an infusion reaction while getting one of these drugs. This is like an allergic reaction, and can include fever, chills, flushing of the face, rash, itchy skin, wheezing, and trouble breathing.

Immune-related side effects: These drugs work by basically removing one of the safeguards on the body’s immune system, which can then sometimes attack healthy organs. This might lead to side effects that can affect almost any part of the body, such as the lungs, intestines, liver, hormone-making glands (especially the thyroid), kidneys, or other organs. These side effects can sometimes be serious and rarely might even be life-threatening.

It’s very important to report any new side effects to your healthcare team right away. If serious side effects do occur, treatment might need to be stopped and you might get high doses of corticosteroids to suppress your immune system.