A Custom Vaccine to Fight Prostate Cancer

A Custom Vaccine to Fight Prostate Cancer

Prostate cancer can be stubborn. It can be prolific in its ability to spread and grow. But you already know this—particularly if you’ve been fighting a very nasty form of the disease that will claim the lives of nearly 30,000 men in 2014. “For men with aggressive metastatic prostate cancer that has spread to the bones or other locations in the body, it can be very disheartening. Especially if they are battling stage 3 or 4 castrate-recurrent prostate cancer that no longer responds to hormone therapy,” says Clif Vestal, M.D., a cancer specialist with USMD Prostate Cancer Center.

Chemotherapy is often the next treatment option once hormone therapy fails to fend off the cancer’s progression. Yet for men whose prostate cancer is clearly growing and spreading, but who are not taking narcotics for cancer-related pain, an immunotherapy treatment—Provenge (sipuleucel-T)—may be a good choice.

“Provenge is a custom vaccine made specifically for each patient using his white blood cells. The vaccine stimulates the man’s immune system to kill prostate cancer cells,” says Dr. Vestal. “We all know that our immune system fights off colds, the flu and other viruses that make us ill. But because cancer cells begin as normal, healthy cells, the immune system doesn’t recognize them as a threat to the body. Provenge works around this by stimulating the immune system to recognize and fight certain proteins that are specific to cancer cells.”

Provenge treatment consists of three cycles that take place over a one-month period. Each cycle consists of two appointments. The first appointment is a three-to-four hour session during which a nurse or technician withdraws white blood cells from the man’s arm—a procedure called leukapheresis.

The white blood cells collected are sent to a manufacturing facility where they are incubated for two days with a fusion of two proteins. One protein stimulates cell growth. The second protein—prostatic acid phosphates (PAP)—is an antigen (a foreign substance that triggers the immune system) found on prostate cancer cells. The PAP antigen actually studs the surface of prostate cancer cells so they look like they are covered with antennas. During the incubation period, the patient’s white blood cells take up the PAP antigen—mimicking its spiky appearance on deadly prostate cancer cells.

These genetically modified white blood cells are then sent back to the treating physician and infused into the patient during a second appointment. This treatment cycle is repeated two more times, two weeks apart.

“When the modified cells with the spiky PAP antigen are infused back into the man’s body, his unmodified white blood cells recognize them as prostate cancer cells. But unlike before, the prostate cancer cells don’t register as healthy cells. They appear to be dangerous foreign bodies that need to be attacked and killed. The immune system beefs up its production of infection-fighting T cells to fuel its assault on the prostate cancer cells,” Dr. Vestal says.

While Provenge attacks cancer cells, it doesn’t shrink tumors or stop metastases. It doesn’t lower a man’s PSA level. In fact, you may not see any change in your PSA level during treatment with Provenge, but that doesn’t mean the vaccine isn’t working.

“The main benefit of Provenge is it can help men with advanced prostate cancer live longer,” Dr. Vestal says. “And that is very important.”

In the IMPACT clinical trial, men treated with Provenge lived longer than men who were not treated with the custom vaccine. Specifically, 37.8 percent more Provenge recipients were alive three years after the start of the study than men who did not receive the vaccine. In addition, Provenge reduced the risk of death by 22.5 percent for patients who received the vaccine.

Treatment side effects are generally mild, with the most common being flu-like symptoms for a day or two, chills, nausea, fatigue, joint ache, fever, headache and back pain. Some men can experience more serious symptoms—mostly infusion reactions such as chest pain, racing heartbeat, irregular heartbeat, dizziness, nausea, vomiting. During its clinical trial, only 1.5 percent of men discontinued treatment due to side effects.

Provenge is covered by Medicare and many private health insurance providers. When it was first approved by the Federal Drug Administration and made available in 2010, it sparked spirited discussion and debate among prostate cancer advocates. Its most vocal critic—Marie Huber, a high-profile Cambridge University-educated biochemist turned New York hedge fund analyst—was discredited when it was learned that she had falsified documents and failed to disclose she had a financial interest in the failure of Provenge. The Securities and Exchange Commission learned she had purchased $236,000 worth of options in Dendreon—the Seattle-based company that manufactures Provenge—betting that its stock price would drop during the controversy. In December 2013, she was fined by the SEC and barred from the securities industry for six months.

Now that the dust has settled, Provenge is providing men with another important treatment option. In fact, the National Comprehensive Cancer Network Prostate Panel lists sipuleucel-T (Provenge) as a category 1 recommendation for first-line treatment of asymptomatic patients with castration-resistant prostate cancer, and a 2a recommendation for second-line treatment for minimally symptomatic patients.

“Provenge can also help men prepare for chemotherapy since it helps boost the immune system,” says Dr. Vestal. “Most importantly, Provenge is another tool in our arsenal that we can use to help men live longer—even in the face of very aggressive metastatic prostate cancer.”

If you or someone you love is battling metastatic, castrate-resistant prostate cancer and would like to know more about the Provenge vaccine, please contact USMD Prostate Cancer Center online or via phone at 1-888-PROSTATE (1-888-776-7828).

To make an
appointment.

Contact us online or Call 1-888-PROSTATE.
 
Our Locations
Take A Tour
Meet Our Physicians
Patient Navigator
USMD in The News
USMD in The Media
Upcoming Events

Urology Website Design | Websites for Doctors Urologists by Vital Element, Inc.