Urologists: Prostate cancer immunotherapy's real promise may yet to be seen

August 1, 2010

Although some urologists are intrigued by what the future may hold for immunotherapy, many aren't sure if sipuleucel-T is the treatment that will transform their approach to prostate cancer.

Question

How will the approval of sipuleucel-T change how you treat men with advanced prostate cancer?

Respondents

Jan Colli, MD
Birmingham, AL

Richard Klein, MD
Sioux Falls, SD

Eric Uhlenhuth, MD
Louisville, KY

Eric Wallen, MD
Chapel Hill, NC

The reported benefits of the drug include extending median survival by 4.1 months and causing fewer side effects than intensive chemotherapy. It also offers an alternative for those men who aren't able to use docetaxel (Taxotere).

In late June, the Centers for Medicare & Medicaid Services said it is launching a year-long national coverage analysis (NCA) to determine whether the immunotherapy "is reasonable and necessary under sections 1862(a)(1)(A) and/or 1862(a)(1)(E) of the Social Security Act." In a statement, Dendreon Corp., the maker of sipuleucel-T, said NCAs "do not impact existing coverage decisions, nor do they restrict local Medicare contractors from covering Provenge."

Urology Times spoke with practicing urologists around the country about the concept of treating advanced prostate cancer with sipuleucel-T.

Although some of the urologists are intrigued by what the future may hold for immunotherapy, many aren't sure if sipuleucel-T is the treatment that will transform their approach to prostate cancer. They also raised questions about the drug, some of which relate to its method of administration and cost.

"I don't think it's a game changer because the survival difference is not gigantic. There is a significant survival benefit when you look at the big picture, but it is just a few months. Whether that provides quality of life is not clear," Dr. Wallen said.

"We also don't know if administered earlier in the course of the disease, if Provenge could be more effective in extending survival and improving the quality of life. I'd love to see it given a clinical trial earlier in the course of treatment, for sure.

"And whether urologists will have access and actually be the ones giving the treatment, rather than medical oncologists, is still very much up in the air. Medical oncologists have the infrastructure to do this kind of treatment with infusions. It's an issue, because most urologists are not set up as cancer centers that can do infusion treatments. I think the company wants urologists to do it, because they know that's where the patients are, but whether that comes to pass remains to be seen."

Will add to quality of life

"Right now, it's one more avenue we can try," she said. "As I understand, it is for advanced prostate cancer, not localized, early-stage prostate cancer. For patients with metastatic disease, Provenge can extend their life for a few months and probably decrease the pain and suffering. We don't have a good treatment now for metastatic prostate cancer. Chemotherapy doesn't work; radiation doesn't work. So this will add to the quality of life and lifespan for those with advanced disease.

"Immunotherapy is definitely the way we're going with prostate cancer," said Dr. Colli, an assistant professor at the University of Alabama specializing in urologic oncology. "Evidence shows that enlisting the immune system does keep prostate cancer in a remission type of state. Studies show patients with low-grade prostate cancer can harbor metastatic cells in their bone marrow and never show signs of advanced metastatic disease for 10 to 20 years. So I believe there is an immune-modulating response."

In Louisville, KY, Eric Uhlenhuth, MD, doesn't see the drug changing the field of prostate cancer treatment.

"My understanding is that it will probably be used for people no longer responding to Taxotere. According to the study, it probably benefits those people, but I don't think it's going to be some paradigm shift in the treatment of prostate cancer where all of a sudden everyone is doing well and will be cured of cancer," Dr. Uhlenhuth said.

"The data doesn't show a dramatic response. Like any other treatment, it carries side effects, so I don't see it making a huge difference."