"I think that many men will be eager to try this agent for their prostate cancer, but it's important to note that the pivotal clinical trials enrolled men with metastatic, castrate-resistant disease, not for earlier stages of disease," said Dr. Charles G. Drake, associate professor of Oncology, Immunology and Urology at Johns Hopkins Sidney Kimmel Comprehensive Cancer Center in Baltimore.
Barri Winiarski, a spokeswoman for Dendreon Corp., the company that makes Provenge, said the company would be able to treat 2,000 patients within the first 12 months. The company's single manufacturing facility for Provenge would be running by early 2011 and two more sites in California and Georgia would be open by mid-2011.
Critics and supporters of Provenge have said there are still questions about the results of the trials and how a cancer treatment could improve survival without actually shrinking cancer tumors.
"One vexing question remains about why Provenge would increase survival without improving progression-free survival, two factors that until now have always gone together," said Dr. Otis Brawley, chief medical officer for the American Cancer Society said in a statement.
" But even those who do not know why this could be have come around to agree this approach works and will soon be using it on patients who fit the criteria," he said.
Several more months of life might not be considered a "home run," but the method of treatment and the small step in a new direction has prostate cancer advocates and other cancer researchers excited.
"All of us want to see home runs, but the reality is we don't have something like that," said Dr. Nina Bhardwaj, director of the Tumor Vaccine Program at New York University Langone Medical Center in New York City. "Even in cancer when new chemo drugs are coming out if you can improve survival by four to six months, it's a big step."
"This represents a small but significant improvement and supports approaches that use of cell-based vaccines to treat cancer," said Bhardwaj.
However, as Bhardwaj predicted, cell-based vaccines like Provenge will be expensive. Patients have to pay for the expensive process of extracting the blood, the processing of the blood and the transport of all the samples.
"Being individualized therapy like that makes it expensive -- just like the bone marrow transplant," said Bhardwaj.
A spokeswoman from Dendreon Corp. said the company "has not yet set the price, however we expect it will be similar to other novel biologics that prolong survival."
Other "novel biologics" run from $50,000-$100,000 for a course of treatment.
However experts still see Provenge as a door to more research for various forms of cancer.
"We can now look forward to additional studies of this approach in breast cancer and melanoma, and eventually in other diseases," said Brawley. "Many experts feel the real impact of this immunotherapy approach may be more significant for cancer overall than for prostate cancer alone."