But, this may also prove to be a hurdle in getting U.S. Food and Drug Administration approval to study the vaccine in humans. "The FDA requires that the active proteins be well characterized, and we don't know which the active proteins are," Vile said.
Even so, he said, "we hope to try to put this vaccine into patients within the next three to five years."
Dr. J. Leonard Lichtenfeld, deputy chief medical officer for the American Cancer Society in Atlanta, said that news of the study "certainly holds out hope that this may represent a true advance."
He cautioned, though, that "we have been looking to vaccines for cancer for many decades and have not yet seen a vaccine or immune therapy make the leap from interesting concept to something effective in the clinic."
That said, the approach outlined in the new paper is "very different," Lichtenfeld said, adding that he remains cautiously optimistic about the vaccine.
"We have been excited in the past by some of these reports, and the success has not panned out," he said. "There is still a ways to go before we can get excited and say it will have benefit for patients with prostate cancer."
Willem W. Overwijk, a cancer vaccine researcher at the University of Texas MD Anderson Cancer Center in Houston, agreed. "We have to wait and see if it will work in people," he said. "They are inducing a broad immune response at many targets on the tumor, which makes it harder for the tumor to escape. [If it does], they make a new vaccine targeting the recurring tumor."
But the bottom line remains: "We have to see if this works the same way in people with prostate cancer," Overwijk said. "Stay tuned."
All rights reserved