Immunotherapy is a type of cancer treatment that helps your immune system detect and fight cancer cells. Treatments may be administered via a catheter, intravenously, or by injection.

There are several different treatment options available for bladder cancer. One of these is immunotherapy, a type of treatment that works to boost your immune system’s response to the cancer.

You may only think of your immune system in the context of protecting you from infections. However, it can also recognize and respond to cancer cells as well.

Despite this, cancer cells have ways to evade the immune system. This often includes mechanisms that make them less visible to immune cells. When immune cells can’t “see” a cancer cell, they can’t get rid of it.

This is where immunotherapy comes in.

There are three different types of immunotherapy for bladder cancer. The goal of each is to give your immune cells the boost they need to detect and destroy cancer cells.

Keep reading to learn more about the types of immunotherapy used for bladder cancer treatment and how effective they are.

When is immunotherapy used for bladder cancer treatment?

Immunotherapy is commonly used for advanced types of bladder cancer or to prevent the cancer from returning after surgery, according to Cancer Research UK.

Several factors may help a doctor determine if immunotherapy is right for you, including:

  • the stage of the cancer
  • the size of the cancer
  • how quickly the cancer is growing
  • the genetic makeup of the cancer
  • which treatments have been used already, if any
  • whether the cancer has spread to other parts of the body
  • your age and overall health
  • your personal preferences

Intravesical immunotherapy treatments are most commonly used for early stage bladder cancer and non-muscle invasive bladder cancer (NMIBC), according to the American Cancer Society (ACS).

In intravesical immunotherapy, a foreign body is introduced to the bladder directly as a liquid using a catheter. This triggers an immune response, which the immune cells respond to and then go on to respond to the bladder cancer.

There are three types of intravesical immunotherapies for bladder cancer:

  • BCG: Bacillus Calmette-Guerin (BCG) is the most common intravesical therapy and is one of the oldest immunotherapies for cancer, first used in 1976. It’s a type of bacteria related to the bacterial species that causes tuberculosis.
  • Nadofaragene firadenovec (Adstiladrin): Approved by the Food and Drug Administration (FDA) in 2022, this type of gene therapy is important for interferon alfa-2b, which helps the cells in the bladder’s lining fight against cancer cells. A doctor will administer the drug once every 3 months.
  • Nogapendekin alfa inbakicept (Anktiva): First approved by the Food and Drug Administration (FDA) in 2024, this interleukin-15 (IL-15) receptor agonist helps boost T and NK cells in the immune system to fight off cancer cells.

How effective is intravesical immunotherapy?

BCG treatment is the most common immunotherapy for cancer and is often the first-line option for bladder cancer.

According to a 2020 review, BCG is effective in treating up to 65% of high risk papillary tumors and 75% of localized tumors. That said, the authors note that as many as 25% to 45% of people don’t benefit from treatment with BCG.

What are the side effects of intravesical immunotherapy?

Some possible side effects of intravesical immunotherapies may include:

Immune checkpoints are systems that help prevent your immune system from attacking healthy cells in your body. However, immune checkpoint proteins on cancer cells can prevent the immune system from detecting them.

Immune checkpoint inhibitors help block immune checkpoints from working as they should. This helps immune cells, specifically T cells, to find and destroy cancer cells. These medications most commonly target PD-1 and CTLA-4 proteins.

The FDA has approved five types of immune checkpoint inhibitors for bladder cancer, including:

Immune checkpoint inhibitors may be used when bladder cancer has spread into the bladder muscle wall, nearby lymph nodes, or even more distant tissues. It can also be used after surgery to help prevent the cancer from coming back.

How effective are immune checkpoint inhibitors for bladder cancer?

A 2021 clinical trial found that participants who took Opdivo after bladder cancer surgery had an increased median disease-free survival of 10 months compared to those who took a placebo.

Similarly, a 2024 clinical trial found that taking pembrolizumab (Keytruda) after receiving bladder surgery may double the length of time it takes before bladder cancer returns compared to people who did not receive any further treatment.

What are the side effects of immune checkpoint inhibitors?

All immune checkpoint inhibitors are given intravenously (via IV). There are several side effects associated with immune checkpoint inhibitors, including:

Monoclonal antibodies are manufactured antibodies that target specific aspects of cancer cells. When a monoclonal antibody binds to its target on a cancer cell, it marks that cell for destruction by the immune system.

The types of monoclonal antibodies used for bladder cancer are called antibody-drug conjugates (ADCs). This is when a chemotherapy drug is attached to a monoclonal antibody. When the monoclonal antibody binds to its target, it delivers the chemotherapy drug directly to the cancer cell.

The FDA has approved two ADCs for bladder cancer, to be given intravenously:

ADCs are typically used for more advanced bladder cancers. They may be recommended when other treatment combinations, typically involving chemotherapy and immune checkpoint inhibitors, have already been tried.

How effective are ADCs for bladder cancer?

ADCs may benefit people with bladder cancer who’ve previously received other treatments.

For example, a 2021 clinical trial found that Padcev significantly improved overall survival and progression-free survival compared to chemotherapy. The incidence of side effects of both Padcev and chemotherapy were similar.

What are the side effects of ADCs?

Some of the potential side effects of these monoclonal antibody treatments include:

In addition to immunotherapy, several other treatments are also used for bladder cancer, including:

A doctor will help develop the best treatment plan for you.

Immunotherapy is one of the potential treatments for bladder cancer. It works by helping your immune system respond to cancer.

There are three types of immunotherapy used for bladder cancer, including intravesical treatments, immune checkpoint inhibitors, and ADCs.

Whether immunotherapy is used for bladder cancer depends on many factors. If immunotherapy is recommended for your bladder cancer, be sure to ask your care team about the various benefits and risks associated with it.