Immunotherapy for penile cancer

Immunotherapy helps to strengthen or restore the immune system’s ability to fight cancer. This works to kill cancer cells and stop them from growing and spreading.

Penile cancer is sometimes treated with immunotherapy. If you have immunotherapy, your healthcare team will use what they know about the cancer and about your health to plan the drugs, doses and schedules.

Immunotherapy may be the only treatment you have or it may be used along with other cancer treatments. You may have immunotherapy to treat:

• stage 0 penile cancer as a topical cream

• advanced penile cancer that has spread from where it started to nearby tissue, lymph nodes or other organs as a systemic therapy

Different types of immunotherapy are used for penile cancer.

Toll-like receptor agonists are immunotherapy drugs that bind to toll-like receptors and cause an immune response that kills cancer cells. When the receptors detect cancer cells or germs, this signals immune cells to attack.

Imiquimod (Aldara) is a toll-like receptor agonist that is sometimes used to treat stage 0 penile cancer, including penile intraepithelial neoplasia (PeIN). It’s given topically as a cream. It’s usually applied directly to the abnormal area a few times a week for several weeks.

The immune system normally stops itself from attacking normal cells in the body by using specific proteins called checkpoints. Checkpoints slow down or stop an immune system response. Some penile cancer cells use these checkpoints to hide and avoid being attacked by the immune system. Immune checkpoint inhibitors work by blocking the checkpoint proteins so immune system cells (called T cells) attack and kill the cancer cells.

Immune checkpoint inhibitors are given as a systemic therapy by a needle into a vein (intravenously, or by IV). The following immune checkpoint inhibitors target the PD-1 checkpoint protein and may be used for penile cancer.

Pembrolizumab (Keytruda) may be used to treat metastatic penile cancer if the tumour has certain genetic changes (mutations) called high microsatellite instability (MSI-H) or mismatch repair deficiency (dMMR). Pembrolizumab may be offered only when the tumour can’t be removed by surgery, doesn’t respond to previous treatments and there are no better treatment options available.

Cemiplimab (Libtayo) may be used to treat locally advanced or metastatic penile squamous cell carcinoma (SCC) that can’t be removed by surgery or treated with radiation therapy.

Side effects of immunotherapy will depend mainly on the type of drug or drug combination, the dose, how it’s given and your overall health. Tell your healthcare team if you have side effects that you think might be from immunotherapy. The sooner you tell them of any problems, the sooner they can suggest ways to help you deal with them.

The side effects of topical immunotherapy are very different from those of systemic immunotherapy.

Topical imiquimod may cause these side effects:

• red, itchy skin in the treated area and nearby skin
• burning and pain in the treated area
• swelling (edema)
• discharge from the wound

Pembrolizumab and cemiplimab may cause these side effects:

• skin problems, including itching
• fatigue
• diarrhea
• pain or stiffness in the joints (arthralgia)
• thyroid problems
• nausea and vomiting

All drugs, including those used to treat cancer, are approved for use in Canada by Health Canada. If a drug is mentioned on cancer.ca, it means that Health Canada has approved the drug and pharmaceutical companies sell it in Canada. It does not mean that the drug is offered everywhere in Canada.

Paying for drugs is the responsibility of provincial and territorial health departments. Each health department makes its own decisions about which drugs to cover (pay for) in that province or territory. This means that a drug may be covered in one province, but not in others.

Your oncologist will talk to you about different drug treatments and what is available through your provincial or territorial drug program.

Find out more about immunotherapy. To make the decisions that are right for you, ask your healthcare team questions about immunotherapy.

Details on specific drugs change regularly. Find out more about sources of drug information and where to get details on specific drugs.