EVMS doctor helps develop new cancer vaccine

A federal agency could be about to approve a revolutionary prostate cancer vaccine that a local doctor played a major role in researching.

Industry experts and advocacy groups say signs are positive that the U.S. Food and Drug Administration will approve the vaccine called Provenge, which stimulates the body's immune system to fight cancer cells. A decision is due this week.

Dr. Paul Schellhammer, an investigator in the trials and a urology professor at Norfolk's Eastern Virginia Medical School, has studied the vaccine for more than a decade. About 40 local patients were part of the clinical studies the FDA is considering.

While the treatment's benefits are modest - it extended lives an average of 4-1/2 months - it's gaining worldwide attention because it is the first vaccine of its type in the battle against cancer and could lead to other immune-based therapies.

The vaccine could be an important new tool, with milder side effects than treatments such as chemotherapy, surgery and radiation therapy.

"It's a fourth modality, and works markedly different from other treatments available," Schellhammer said Tuesday. "It's a kinder, gentler therapy."

While vaccines are generally thought of as preventive, Provenge is a therapeutic vaccine made from the patient's own white blood cells. The cells are removed from the patient, treated with the drug and infused back into the patient. The treated cells then cause an immune response, which kills cancer cells while leaving normal cells unharmed.

Provenge was developed by Seattle-based Dendreon Corp., which conducted initial studies among men with advanced prostate cancer who had already failed standard hormone treatment. The vaccine extended life by an average of 4-1/2 months, although some lives were lengthened by two to three years.

The only side effects were mild flu-like symptoms, according to the study results.

Dr. Otis W. Brawley, chief medical officer for the American Cancer Society, said in an e-mail response that many experts think the real impact of this vaccine is the "immunotherapy" approach it takes. While the benefit for people with advanced stages of prostate cancer is modest, "We can now look forward to additional studies of this approach in breast cancer and melanoma, and eventually in other diseases," Brawley said.

While there are other cancer vaccines on the market, they work like traditional vaccines to prevent infection with viruses that can cause cervical and liver cancer.

This cancer-treatment vaccine works by boosting the immune systems of people who already have tumors.

The American Cancer Society estimates that more than 192,000 new cases of prostate cancer are diagnosed in the United States each year, and 27,360 men die of the disease.

Schellhammer said the research has been a long and difficult process, full of setbacks. A pproval would be a pat on the back for the researchers at EVMS and Urology of Virginia. However, he cautioned, "it's not done until it's done."

The FDA was expected to approve Provenge in 2007 after an advisory panel recommended it, but the agency put off the final vote after critics said more information was needed on its benefits and risks. That move angered some advocates for the vaccine, who protested before FDA headquarters.

A second, larger study of about 500 people was conducted at 40 sites, and positive safety and effectiveness results were reported last April.

After that report, the vaccine was offered to people in the study who had received placebos, or inert treatments. Schellhammer said there are people still using the vaccine in what's called a "compassionate use" category, but only a limited number.

Schellhammer warned, though, that even if the approval is given, it could take a while for the treatment to reach people: "It's not mass-produced; it's an individual process where cells are drawn, sent through a process, and then returned for infusion."

Elizabeth Simpson, (757) 446-2635, elizabeth.simpson@pilotonline.com