Dendreon’s stock rocketed up 33 percent today on good news for its Provenge treatment for prostate cancer. The Seattle biotech company (NASDAQ: [[ticker:DNDN]]) said today that an independent board of trial monitors reported that patients on Provenge have a 20 percent lower risk of death than those on a placebo in an ongoing trial of 500 men, there were no safety concerns, and that the trial should continue to a final analysis in the middle of 2009.
The company’s shares climbed $1.73 to $6.03 at the close.
The interim results from the trial, called Impact, are consistent with combined findings from a pair of earlier trials that enrolled more than 200 patients, Dendreon CEO Mitchell Gold said in a statement. If Dendreon can show Provenge offers a 22 percent lower risk of death in the ongoing trial at the final analysis, then it will hit the study’s primary goal of extending lives. This trial is being closely watched by patients and investors because it could pave the way for the first treatment ever approved to actively stimulate the immune system to fight cancer cells like a virus.
“We look forward to the final results next year and the opportunity to make Provenge available to the many men with advanced prostate cancer who currently have few appealing treatment options,” Gold said in a statement.
Provenge, called an immunotherapy, or a cancer vaccine, has captivated the public imagination because it doesn’t work like a traditional cancer drug, as we wrote in this preview of the trial in July. Blood is drawn from a patient, and some white blood cells vital to the immune system, called dendritic cells, are separated in a lab. The cells are shipped to the company and incubated with a genetically engineered version of a protein found on prostate cancer cells, called PAP. This is supposed to train the white blood cells to recognize the protein as an invader. The revved-up white blood cells are shipped back and re-infused into the patient, where they recruit the immune system’s arsenal to attack tumor cells that contain PAP.
The company has also been at the center of controversy. An FDA advisory panel recommended in March 2007 that Provenge be approved based on an earlier study showing it prolonged life of prostate cancer patients, while the FDA said it preferred to wait to see confirmation from the ongoing, larger study.
The results could have been better for Dendreon. There was a chance that the company could have pulled together the interim clinical trial results as the basis for a quick filing for approval with the FDA. The company made no indication of that in its press release, so some investors could still conclude there’s plenty of risk between now and the middle of 2009 on whether Provenge’s results will really be good enough to win the FDA’s blessing.
