In the United States, prostate cancer is one of the most common forms of cancer.
However, there are emerging therapies that have shown promise in treating prostate cancer. An example is immunotherapy. Immunotherapy is a treatment method aimed at boosting the immune system’s abilities to fight off cancer cells.
Here we will go through everything that men should be aware of when it comes to treating prostate cancer with immunotherapy.
Fast facts on immunotherapy for prostate cancer
Here are some key points about immunotherapy for prostate cancer. More detail and supporting information is in the main article.
- Immunotherapy is a departure from traditional treatment methods, which either remove or kill cancerous cells.
- The treatment has many potential risks, mostly associated with taking the medications.
- Immunotherapy is an umbrella or overarching term that can include vaccines and monoclonal antibody drugs.
- Side effects related to the treatment include flu-like illness.
In the treatment of prostate cancer, there are two potential approaches for immunotherapy.
- Individualized medicine, where a doctor removes a man’s immune cells and genetically modifies them with cancer-killing properties. The altered cells are then put back into the bloodstream with the hopes they will fight off cancer cells and continue to multiply.
- Blocking medications, where men take special drugs that block a particular aspect of a cancer cell known as a checkpoint. This part of the cancer cell works to inhibit the immune system, preventing it from fighting back against the cancer.
The field of immunotherapy is an emerging and promising one for cancer treatments. However, it is still in its early stages when compared to more traditional cancer treatments, such as radiation and chemotherapy.
However, the United States Food and Drug Administration (FDA) have approved an immunotherapy drug to treat prostate cancer in men.
Immunotherapy in the treatment of prostate cancer is a relatively new practice, so there is not always comprehensive information about the potential long-term effects of the treatment.
What researchers do know is that there are potential risks to an overactive immune system. “Supercharging” the immune system with medications can cause immune cells to attack healthy tissues.
These may not be limited to just the prostate but could also affect the:
- other organs
These medications can result in inflammation of the tissues, which could prove harmful and perhaps deadly for those people taking the drugs.
Researchers are now studying different combinations of immunotherapy medications in the treatment of prostate cancer. It appears that taking medication combinations seems to cause more serious symptoms than taking a single immunotherapy.
Researchers are currently conducting trials for immunotherapy drugs for the treatment of prostate cancer and other cancer types.
The FDA have approved the medication Provenge (sipuleucel-T) for administration in men with prostate cancer.
Specifically, doctors can prescribe the drug to treat metastatic, hormone-resistant prostate cancer. Although the drug is classified as a vaccine, each administration of Provenge is made specifically for each man.
To do this, doctors take a sample of a man’s blood and remove white blood cells from the sample for enhancement. In a laboratory, technicians use special chemicals to “train” the man’s immune system cells to seek out and kill prostate cancer cells.
Technicians do this by exposing the cells to a protein called prostatic acid phosphatase (PAP), which prostate cancer cells make. These enhanced cells adapt and learn how to kill the prostate cancer cells more effectively.
Once technicians have prepared the cells, the treatment is given to men with prostate cancer via IV infusion, usually every 2 weeks for 6 weeks.
The medication and infusion approach does not cure cancer. However, the research on Provenge shows that it can help a man with an otherwise poor prognosis live several months longer, according to the American Cancer Society.
Side effects may occur, including:
- muscle aches
These symptoms do not usually last beyond 3 days after the infusion.
Traditionally, prostate cancers have not been as responsive to immunotherapy treatments as other cancer types have been. Provenge is a drug that has been specifically approved to treat prostate cancer.
There are a few stipulations a man must meet before doctors treat him with Provenge. These include:
- men whose cancer has spread beyond the prostate
- men whose cancer has been resistant to hormone therapies
- men who are not currently experiencing a significant level of pain related to their cancer
Some of the names for these types of prostate cancer include:
- metastatic, asymptomatic, hormone-refractory prostate cancer
- metastatic castrate-resistant (mCRPC)
- androgen-independent (AI) prostate cancer
Researchers have not identified a genetic marker associated with particular prostate cancer types that would help doctors narrow down which men would most benefit from immunotherapy treatments.
Because immunotherapy is still considered experimental, the medication is not usually given to men whose prostate cancer would respond to other types of treatment that have been better researched.
The medication is very expensive; the average price for the treatment can reach six figures. As newer treatments become available, the list of immunotherapies and the types of prostate cancer and symptoms that can be treated will likely expand.
While Provenge is the only FDA-approved vaccine and immunotherapy for prostate cancer, a doctor may prescribe other immunotherapies that have been specifically designed for other conditions, but may still be effective for prostate cancer.
Research is being done on further immunotherapy medications for prostate cancer.
One such example is a vaccine called PROSTVAC, a medication that does not need to be tailored to a person’s particular white blood cells.
The trial, known as PROSPECT, is currently in phase III trials. The purpose of phase III trials is to ensure the safety and effectiveness of the drug by enrolling up to 3,000 participants and monitoring their reactions to the drug.
If the results are promising, the study could go to larger phase IV trials. However, phase III trials are not an indicator that the medication will gain FDA approval.