When is intravesical therapy used?
Intravesical therapy is used mainly for some early-stage bladder cancers that are still only in or very close to the inner lining of the bladder, where almost all bladder cancers start.
Drugs given directly into the bladder affect the cells lining the inside of the bladder but have very little effect on cells elsewhere. This means that intravesical therapy isn’t likely to be helpful in treating cancer cells that have grown deeply into the bladder wall, or cancer cells in other parts of the body.
After a transurethral resection of bladder tumor (TURBT)
A TURBT is often done both to confirm the diagnosis of bladder cancer and to see how deeply it has invaded into the bladder wall. Often, a single dose of intravesical chemotherapy (see below) is given within a day of the TURBT. This can help lower the risk of bladder tumors coming back later.
To treat non-muscle invasive bladder cancer (NMIBC)
These early-stage cancers have not grown deep enough to reach the muscle layer of the bladder wall, nor have they spread to other parts of the body. This includes cancers that:
- Are only in the inner lining of the bladder (stage 0 bladder cancers, including carcinoma in situ [CIS])
- Have grown only into the layer below the lining (stage I bladder cancers)
Most often, intravesical therapy is used after a TURBT.
As noted above, a single dose of intravesical chemotherapy is usually given within 24 hours of the procedure.
If further intravesical treatments (immunotherapy or chemotherapy) are needed, they're usually started a few weeks later. Treatment schedules vary, depending on the risk of the bladder cancer coming back after treatment, which treatment is used, how well the cancer responds to the treatment, and other factors:
- For some low-risk cancers, no further treatment might be needed.
- For intermediate- and high-risk cancers, intravesical therapy is often given weekly for about 6 weeks, and then less often (for about a year for intermediate-risk cancer or up to 3 years for high-risk cancer).
Your doctor will talk with you about a treatment schedule based on your bladder cancer and how it responds to treatment.
To treat muscle invasive bladder cancer (MIBC)
These cancers have reached the muscle layer of the bladder wall.
If a TURBT is done as the initial surgery (which isn’t often for MIBC), a dose of intravesical chemotherapy is often given within 24 hours. But intravesical therapy isn’t likely to be helpful for most stage II or higher bladder cancers because they have already spread beyond the inner lining of the bladder wall.
More advanced bladder cancers are rarely treated with intravesical therapy.
Types of medicines for intravesical therapy
There are 2 main types of medicines used in intravesical therapy:
- Immunotherapy
- Chemotherapy
Intravesical immunotherapy
Immunotherapy helps the body’s own immune system attack the cancer cells.
Bacillus Calmette-Guerin (BCG)
BCG is the most common intravesical immunotherapy for treating early-stage bladder cancer.
BCG is a vaccine made from a germ that's related to the one that causes tuberculosis (TB), but it doesn’t cause serious disease. When BCG is put into the bladder as a liquid through a catheter, it helps "turn on" the immune system cells there, which then attack the bladder cancer cells.
Side effects of BCG: Treatment with BCG can cause a wide range of symptoms. It's common to have flu-like symptoms, such as fever, aches, chills, and fatigue, which can last for 2 to 3 days after treatment. It can also cause a burning feeling in the bladder, the need to urinate often, and even blood in the urine.
While getting BCG doesn’t usually make people very sick, serious BCG infections can occur in people who have a weakened immune system. Though these infections are rare, this treatment typically isn’t recommended for people with weakened immune systems.
If a serious infection does happen, one sign of this can be a high fever that doesn't go away. If this happens, call your doctor right away.
You might want to ask about other serious side effects you should watch for and call your doctor about.
Nadofaragene firadenovec (Adstiladrin)
This treatment is made up of a virus that contains the gene to make interferon alfa-2b, an important immune system protein. When the virus is put into the bladder as part of a liquid, it delivers the gene into the cells lining the bladder wall. The cells then start making extra interferon alfa-2b, which helps the body’s immune system attack the cancer cells. Because this treatment involves adding a gene to some cells in the body, it can be thought of as a type of gene therapy.
Adstiladrin can be used to treat NMIBC that is at high risk of returning and that isn’t being helped by treatment with BCG. It is typically given once every 3 months.
Side effects of Adstiladrin: Some people getting this treatment might have side effects such as feeling tired, having bladder spasms, feeling the need to urinate often, or having blood in the urine.
The virus used in this treatment doesn’t usually cause disease in people with healthy immune systems. It’s just a way to get the gene inside the cells. Still, this is a live virus that might cause more serious infections in people who have weakened immune systems. Because of this, this treatment typically isn’t recommended for people with a weakened immune system.
Nogapendekin alfa inbakicept (Anktiva)
This medicine is an interleukin-15 (IL-15) receptor agonist. When put into the bladder as a liquid, it activates some of the body’s immune cells, including natural killer (NK) cells and T cells, which then attack the cancer cells.
Anktiva is used along with BCG to treat NMIBC that hasn't been helped by treatment with BCG alone. Both drugs are typically given once a week for 6 weeks, then less often for up to about 3 years, for as long as they are still helpful.
Side effects of Anktiva: Side effects from this medicine can include bladder symptoms such as pain or burning when urinating, blood in the urine, or having to go more often. Because this medicine is given along with BCG, side effects from BCG (see above) are also possible.
Intravesical chemotherapy
For this treatment, a chemotherapy (chemo) drug is put right into the bladder through a catheter. These drugs kill actively growing cancer cells. Many of these same drugs can also be given systemically (usually into a vein) to treat more advanced stages of bladder cancer. Intravesical chemotherapy is most often used when intravesical immunotherapy with BCG doesn't work or if it isn’t available.
Gemcitabine and mitomycin are the drugs used most often for intravesical chemotherapy.
Other chemo drugs such as valrubicin, epirubicin, and docetaxel might also be options in some situations.
Researchers are also studying newer ways of delivering these drugs that might help them work better (see What’s New in Bladder Cancer Research?).
Side effects of intravesical chemo: The main side effects of intravesical chemo are irritation and a burning feeling in the bladder, and blood in the urine.
A major advantage of giving chemo right into the bladder instead of injecting it into the bloodstream is that the drugs usually do not reach and affect other parts of the body. This helps people avoid many of the side effects linked to chemo.