The second leading cause of death behind cardiovascular disease within the broader spectrum of cancers is prostate cancer. It’s the second most common cancer among American men. About one in six men will be diagnosed with prostate cancer.
Many men diagnosed are treated with surgery or radiation, and many can be cured of their prostate cancer. But one in three have a recurrence of their cancer following their initial treatment. Once the cancer is acquired, it’s common to put men on hormone therapy. That’s the standard of care, and of men who start this hormone therapy about four and five eventually have further progression developed.
Even with appropriate treatments like surgical removal of the prostate or various forms of radiotherapy, the cancer can progress from an early stage to an advanced stage. The tumor is no longer localized in the advanced stage but has become a metastatic disease and hormone-refractory disease.
In metastasis, cancer cells break away from where they first formed (primary cancer), travel through the blood or lymph system, and develop new tumors (metastatic tumors) in other parts of the body.
Hormone-refractory prostate cancer refers to a disease that initially responds to drugs that block male hormones from fueling cancer. Still, eventually, the tumor becomes refractory to treatment, meaning the treatment has stopped working.
Often when it’s early and localized, prostate cancer doesn’t cause any symptoms. When it’s advanced, people can develop symptoms related to the spread of their cancers. In the last five years, there have been quite a few advancements and drug approvals in the United States, which are effective treatment alternatives for men with advanced prostate cancer.
In the last few years, there are two new drugs considered hormone therapies for advanced prostate cancer. One type of treatment vaccine called Sipuleucel-T (Provenge) is approved for men with few or no symptoms from metastatic prostate cancer.
What Is Provenge? How does it work?
Provenge is established as FDA-approved cellular immunotherapy used to treat certain men with advanced prostate cancer. Immunotherapy is personalized therapy. The goal of personalized treatments such as Provenge is to provide a safe and effective way to treat patients. In this case, to treat patients using their own immune system.
Provenge is autologous cellular immunotherapy. That means it’s a treatment derived directly from each patient utilizing the patient’s genetically engineered immune cells.
Provenge is indicated for the treatment of asymptomatic or minimally symptomatic metastatic castrate-resistant prostate cancer (MCRP). This form of prostate cancer spreads outside the prostate and then has stopped responding to hormonal therapies. Don’t let the term “castrate” make you nervous. It just refers to when hormonal therapies stop working.
Provenge, which is the brand name, was approved in 2010 to treat advanced prostate cancer. UCLA was involved in the studies that led to the approval, and doctors have been giving men with advanced prostate cancer Provenge since 2003. So, for over eighteen years, it has been used as a treatment.
Understanding Cancer Immunotherapy
To give a little background to understand better how Provenge immunotherapy works, let’s talk about the immune system mechanics and cancer mechanics.
Cancer has several features:
- It can grow its own blood vessels
- Has the ability to grow without restrictions
- The ability to avoid the immune system
The ability to avoid the immune system is considered the hallmark of cancers. Oncologists believe that the immune system can recognize and prevent cancers from developing or prevent them from growing and spreading.
Called immune surveillance, the immune system cells, such as natural killer cells, cytotoxic T cells, or macrophages, monitor the body for abnormal cells. When errant cells are detected, they are destroyed before becoming self-replicating tumors.
The immune system can suppress tumor growth and development, or certain circumstances can allow tumor growth. This is a dynamic process where the body tries to control the tumor. A tumor can sometimes do things to evade or outgrow the ability of the immune system to recognize and control it.
Provenge Immunotherapy is designed to boost the immune system to target and attack advanced prostate cancer as it tries to outmaneuver the immune system.
Provenge is a therapeutic vaccine for cancer. There is a difference between a preventative vaccine and a therapeutic vaccine.
A preventative vaccine is explicitly designed to prevent someone from developing a disease. Provenge DOES NOT prevent prostate cancer; it’s considered a therapeutic vaccine. Provenge is designed to treat cancers that are already developed. The therapy is intended to:
- Delay or stop cancer cell growth
- Cause tumor shrinkage
- Prevent cancer from coming back
- Eliminate cancer cells not killed by other forms of treatment
Provenge works as a cancer vaccine using resting immune cells, the white blood cells, the same cells fighting infections in your body. Taken out of the patient, they are sent to a facility where they’re activated with a particular type of protein known as PAP. PAP is a protein that is highly expressed in more than 95% of all prostate cancers.
When these cells become activated, an IV infusion returns them to the patient. Inside the patient, they multiply and grow and can recognize an attack the prostate cancer.
This process occurs two more times. The Provenge treatment process can be completed in six appointments throughout the course of about a month. With Provenge, cells are ready to target and attack prostate cancer. Provenge extends the life of certain men with MCRP.
Treatment Window – eligibility to receive Provenge
There’s a treatment window for where men are eligible to receive Provenge. When metastatic prostate cancer develops, there is a relatively minimal spread outside the prostate and may cause no symptoms or relatively few symptoms. When there is more extensive cancer in the bones and the lymph nodes, this causes more significant symptoms.
This is important for two reasons. Immune therapies work better with more minimal disease. Provenge is only approved for men who have either a few or no symptoms from a practical standpoint, which is a specific FDA indication.
There are other forms of therapies such as chemotherapies and hormonal therapies for people with more extensive disease and more symptoms related to their cancers.
Why use Provenge?
Provenge has been shown in several large phase 3 studies to help men with advanced prostate cancer live longer. So, this is not a cure for men with advanced prostate cancers, but it is a way of extending the lifespan of men who have cancer that has spread outside the prostate.
Provenge is generally well tolerated. The most common effects are mild to moderate chills, fatigue, fever, and back pain. There are occasional more serious adverse events or side effects. Discuss those with your doctor before signing up for Provenge.