Provenge: A Different Kind of Prostate Cancer Treatment

Monday, June 25, 2012

Provenge® (sipuleucel-T) is a unique treatment option for men who have asymptomatic or minimally symptomatic prostate cancer that has spread (metastasized) and also resisted hormone therapy (also referred to as metastatic castrate resistant or hormone refractory prostate cancer). Before the introduction of Provenge, men with this type of prostate cancer had no promising treatment opportunities.
Studies show that hormone resistant prostate cancer progresses rapidly, therefore prompt treatment is critical. In fact, up to 80% of men with hormone resistant prostate cancer develop metastases, and 46% of men with this form of the disease develop metastases in only two years. (Smith 2005; 2011)

What is Provenge?

Provenge is unlike other prostate cancer treatments because it is a form of immunotherapy, which means it is designed to utilize and work with a man’s immune system to fight prostate cancer. In this sense, Provenge is sometimes referred to as a prostate cancer vaccine, because  vaccines are also a form of immunotherapy. However, unlike a true vaccine, Provenge cannot provide immunity against disease.
Provenge is an autologous cellular immunotherapy, which means it uses a man’s own immune cells (autologous) to battle prostate cancer. To accomplish this, a series of carefully orchestrated steps must be followed, with the end result being a drug that is personalized for each patient. Those steps are explained below (“How Provenge Treatment Works”).

How Provenge Differs From Other Prostate Cancer Treatments

The main reason Provenge differs from other treatments for prostate cancer is that it is the only prostate cancer immunotherapy approved by the Food and Drug Administration (FDA) and the first in a new class of therapy to use this approach. Another way to look at Provenge versus other prostate cancer treatments is that while other therapies work against the body–chemotherapy and radiation therapy are toxic and focus on killing cancer cells, while hormone therapy stops production of hormones–Provenge is a positive approach that makes use of the body’s own immune cells (T-cells) which have been activated in a laboratory so they can recognize and battle prostate cancer cells.

Who Can Take Provenge

Dendreon Corporation, makers of Provenge, and The National Comprehensive Care Network recommend Provenge as a first-line treatment for men who meet the following criteria. Let’s take each factor individually.
  • Asymptomatic or minimally symptomatic prostate cancer. This means a man has no cancer pain or if cancer pain is present, it is not severe enough to require treatment with narcotics.
  • Cancer has metastasized. The prostate cancer has spread beyond the source tumor in the prostate to other areas of the body, such as the bones.
  • Resistant to hormone therapy. The patient’s prostate cancer has worsened since undergoing treatment with drugs that stop the production of hormones.
Your healthcare provider can determine if you meet the criteria for treatment with Provenge. Physicians take several other factors under consideration when deciding if a patient is a candidate for Provenge. For example, men who have a lower tumor burden and an otherwise healthy immune system are positive candidates for Provenge. Physicians may also recommend Provenge so men can take advantage of immunotherapy before their disease progresses too far and they are no longer a candidate for treatment with Provenge.

How Provenge Treatment is Prepared

If your healthcare provider decides you are a candidate for Provenge, he or she will not write a prescription and send you off to a pharmacy to fill it. Instead, each dose of Provenge is unique and tailor made for you. Therefore, a series of steps are necessary to create each personalized dose of Provenge using your own blood cells. Here is how the process works.
  • Your doctor will order a complete blood count to check your blood cell levels.
  • To make your personalized dose, you must undergo a process called leukapheresis, which involves having your blood drawn either through a vein or through a central venous catheter placed into a large vein near the heart. The blood flows through a tube to a machine where immune cells, platelets, and some red blood cells are collected from the blood sample. The machine then returns the rest of the cells and the blood to the body. This entire process is an outpatient procedure and takes about 3 to 4 hours to complete. You can read, rest, listen to music, or watch a movie during the procedure.
  • The collected immune cells are sent to a facility where they are activated with a recombinant antigen, which is designed to prompt the immune cells (T-cells) to look for and attack prostate cancer cells. Within 2 to 3 days, the completed personalized dose is then shipped to your doctor or infusion location.
  • The activated immune cells–your personalized Provenge dose–is given by infusion within about three days of the leukapheresis procedure. The infusion process takes about 2 hours: 1/2 hour before the infusion, you will be given acetaminophen or an antihistamine to help reduce the possibility of side effects associated with the infusion. After the one-hour infusion, you will be observed to be sure there are no adverse reactions to treatment.
  • Treatment with Provenge involves three infusions, so you must undergo a second leukapheresis procedure two weeks after the first one, and then a third leukaphersis two weeks after the second one. Each leukapheresis is followed by infusion of the personalized dose of Provenge within three days of the collection process.
To recap: A treatment course with Provenge involves three leukapheresis procedures, each of which is followed within 3 days by an infusion of Provenge. The entire treatment course takes 5 weeks. Because each personalized dose of Provenge has a short shelf life, men who miss an infusion appointment will need to undergo another leukapheresis so clinicians can prepare another dose of Provenge.

How to Prepare for Provenge Treatment

If you and your doctor have decided you will undergo Provenge treatment, be sure to tell your healthcare provider about any medical problems you have, including heart problems, lung disorders, and any history of stroke. Also tell him or her about any medications (both prescription and over-the-counter), vitamins, and other supplements you use.
To prepare for the leukapheresis procedure, it is helpful to follow these tips:
  • Drink more water than you normally do to stay well hydrated
  • Do not drink any caffeinated beverages on the day of your leukapheresis procedures
  • Wear comfortable clothing, including sleeves that can be easily raised above the elbow
  • Eat a breakfast that contains calcium-rich foods, such as almonds, blueberries, bananas, yogurt, and calcium-enriched orange juice or cereal
  • Ask someone to drive you home after the procedure. Many men feel fatigued after leukapheresis.

How Provenge Affects PSA

Doctors typically use the prostate-specific antigen (PSA) test to monitor the progression of prostate cancer and the effects of treatment. Men who take Provenge should know that even if they do not see an improvement in PSA levels, this does not mean Provenge is not working. Provenge can be effective regardless of any changes reflected in PSA levels.

Benefits of Provenge

The goal and primary benefit of Provenge treatment is to help men with prostate cancer live longer. In a clinical study involving 512 men, Provenge reduced the risk of death in men by 22.5%. More specifically, the median survival for the 341 men who took Provenge was 4.1 months longer than that of the 171 men in the placebo group (25.8 months compared with 21.7 months). (Kantoff) In addition, data from Dendreon Corporation note that at three years, 37.8% more patients treated with Provenge were alive when compared with controls. (Dendron)
Another benefit of Provenge treatment is that men who use Provenge can then go on to use other prostate cancer therapies. In fact, because Provenge stimulates the immune system, men who undergo this immunotherapy are often in better condition to handle immunosuppressive therapies, such as chemotherapy.

Side Effects of Provenge

The most common side effects of Provenge treatment, occurring in at least 15% of patients, are back pain, chills, fatigue, fever, headache, joint ache, and nausea. Side effects are generally not severe enough to cause men to stop treatment. In one study, less than 1.5% of men who took Provenge stopped treatment because of side effects.
Infrequently, Provenge can cause serious reactions, including stroke or severe infusion reactions within one day of infusion, which have been shown in 3.5% of patients. Severe infusion reactions may include breathing problems (reduced oxygen level, shortness of breath, wheezing), chills, dizziness, fatigue, fever, headache, high blood pressure, muscle ache, nausea, vomiting, and weakness.
Men who take Provenge should contact their doctor if they experience any of the mentioned side effects as well as any symptoms not listed that concern them.

Powered by Blogger.