Immunotherapy for Bladder Cancer

Immunotherapy is the use of medicines to help a person’s own immune system recognize and destroy cancer cells. This type of treatment is sometimes used to treat bladder cancer.

Intravesical BCG

BCG is a type of bacteria related to the one that causes tuberculosis. While it doesn’t usually cause a person to get sick, it can help trigger an immune response. BCG can be put right into the bladder as a liquid. This activates immune system cells in the bladder, which then attack bladder cancer cells.

For more details on this treatment, see Intravesical Therapy for Bladder Cancer.

Immune checkpoint inhibitors

An important part of the immune system is its ability to keep itself from attacking normal cells in the body. To do this, it uses “checkpoints” – proteins on immune cells that need to be turned on (or off) to start an immune response.

Cancer cells sometimes use these checkpoints to keep from being attacked by the immune system. But newer drugs that target these checkpoints, called checkpoint inhibitors, can help restore the immune response against cancer cells.

PD-1 and PD-L1 inhibitors

Atezolizumab (Tecentriq) and avelumab (Bavencio) are drugs that target PD-L1, a protein on cells (including some cancer cells) that helps keep the immune system from attacking them. By blocking PD-L1, these drugs boost the immune system's response against the cancer cells. This can shrink some tumors or slow their growth.

Nivolumab (Opdivo) and pembrolizumab (Keytruda) target PD-1, a protein on certain immune cells (called T cells) that normally helps keep these cells from attacking other cells in the body. Blocking PD-1 can allow the immune system to attack the cancer cells, which can shrink some tumors or slow their growth.

These drugs can be used in different situations to treat bladder cancer:

• Any of these checkpoint inhibitors can be used in people with advanced bladder cancer that starts growing again after chemotherapy.
• Atezolizumab and pembrolizumab can be used in people who can't get the chemo drug cisplatin (due to things like hearing loss, kidney failure, or heart failure).
• Avelumab can be used as an additional (maintenance) treatment in people with advanced bladder cancer that did not get worse during their initial chemotherapy treatments.
• Pembrolizumab can be used to treat certain bladder cancers that are not growing into the muscle wall of the bladder, are not getting smaller with intravesical BCG, and are not being treated with a cystectomy.

These drugs are given as intravenous (IV) infusions, usually every 2 to 6 weeks, depending on the drug.

Possible side effects

Side effects of these drugs can include:

• Fatigue
• Nausea
• Loss of appetite
• Fever
• Urinary tract infections (UTIs)
• Rash
• Diarrhea
• Constipation

Less often, more serious side effects can occur:

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, feeling dizzy, wheezing, and trouble breathing. It’s important to tell your doctor or nurse right away if you have any of these symptoms while getting one of these drugs.

Autoimmune reactions: These drugs work by basically removing one of the safeguards on the body’s immune system. Sometimes the immune system starts attacking other parts of the body, which can cause serious or even life-threatening problems in the lungs, intestines, liver, hormone-making glands, or other organs.

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

Monoclonal antibodies

Antibodies are proteins made by your immune system to help fight infections. Man-made versions, called monoclonal antibodies, can be designed to attack a specific target, such as a protein on the surface of bladder cancer cells. This means these treatments attack cancers cells but ignore normal cells that don't have the target. This reduces damage to normal, healthy cells.

Enfortumab vedotin (Padcev)

Enfortumab vedotin is an antibody-drug conjugate (ADC), which is a monoclonal antibody linked to a chemo drug.

Bladder cancer cells usually have the Nectin-4 protein on their surface. Enfortumab vedotin is an anti-Nectin-4 antibody attached to a chemo drug (MMAE). The antibody part acts like a homing signal, bringing the chemo drug to the bladder cancer cells with Nectin-4 on them. The chemo enters the cancer cells and kills them.

This drug may be used to treat people with advanced bladder cancer who have already been treated with platinum chemotherapy (such as cisplatin) and immunotherapy (specifically, a PD-1 or PD-L1 inhibitor).

Enfortumab vedotin is infused into a vein (IV), once a week for 3 weeks with one week off.

Common side effects include fatigue, peripheral neuropathy (a type of nerve damage), nausea, taste changes, decreased appetite, diarrhea, rash, hair loss, dry eye, dry skin, itching, and high blood sugar levels.