Promising Prostate Vaccine Developed Locally

SAN FRANCISCO, Jul. 10, 2007 -- When prostate cancer spreads, the prognosis can be grim. However, a Bay Area hospital is hoping a new medication can change that. Doctors are now in phase three clinical trials of GVAX, a prostate cancer vaccine.

Bill Moore may look frail, but he's a fighter. For more than 20 years he's been battling prostate cancer with chemo and radiation, and mostly winning.

Bill Moore, prostate cancer patient: "It was in remission for 10 years. I was really feeling good about that."

But last year he got some bad news.

Bill Moore: "They found out it had gotten into the bone and so when it got into the bone, it started moving rapidly."

Bill had more chemo and radiation, but the cancer spread to his spinal column. Then Bill's doctor told him he qualified for a study on a new prostate vaccine.

Bill Moore: "He said, 'well you're lucky, it's a trial program, it's free' I said, 'that sounds good (laughs), sounds good, I think I'll take it.'"

CPMC oncologist Dr. Ari Baron is heading up the clinical trial on the GVAX prostate vaccine. Developed by Cell Genesys, Inc., a South San Francisco company. It's specifically designed for metastatic prostate cancer.

Ari Baron, M.D., CPMC oncologist: "Usually we think of vaccines as prevention. We're trying to prevent the flu or prevent smallpox. In this case we're really trying to treat a disease that has already set in."

Dr. Baron says the vaccine is also designed to be safe for patients like Bill.

Dr. Ari Baron: "It's basically made up of prostate cancer cells that have been altered in a way so they can no longer replicate."

Bill already completed the first vaccine series. Now he's back for maintenance. The treatment isn't easy. Every two weeks after getting a numbing cream on his skin, Bill gets six shots in either his arms or his legs. Today it's his legs.

Bill Moore: "My legs and arms look like it too, look like a pin cushion."

The vaccine is placed just under the skin to trigger an immune response.

Dr. Ari Baron: "White blood cells in your skin see these foreign cells. They're stimulated then to respond to them, if you will, and train your immune system to make perhaps antibodies or t-cells against the prostate cancer. That's how the theory goes."

Everyone in the clinical trial gets the vaccine, but patients like Bill with aggressive cancer get chemotherapy infusions. Although the research is still early, so far it's very promising.

Dr. Ari Baron: "Early data from smaller studies with 40, 50 patients seems to imply, yes, it's both safe and effective. But truly these clinical trials which will have 600 patients in them are the studies that will determine that for sure."

Bill says even the poking has been worth it and he's glad he's part of the vaccine study.

Bill Moore: "It gave me a longer life. Yes, I'm real pleased."

And he's hoping for even more years ahead.

California Pacific Medical Center is recruiting patients for its trials.