Dendreon Immune Booster for Prostate Cancer Helps Men Live Longer; Shares Boom

for patients was “consistent” with previous trials, and so was the side effect profile, Gold says. (An earlier trial of 127 men showed a median benefit of 4.5 months of extra survival time.) When researchers dug deeper into various subpopulations of patients with less aggressive and more aggressive tumor types, and filtered patients based on other characteristics that might have biased the result, Dendreon still saw an across the board benefit, Gold said.

“The results are unambiguous,” Gold said. “It was a clear hit on the pre-specified endpoint of overall survival.”

The positive finding has multiple implications for Dendreon’s business. It will plan to commercialize the drug by itself in the U.S., building a sales team of about 100 representatives to call on urologists and oncologists, Gold said. It will seek a partner to help commercialize the drug in Europe, he said. Dendreon will wrap up some final remaining questions FDA has about its manufacturing processes at a factory in New Jersey, and get ready to start pumping out commercial product after the FDA completes its six-month review of the company’s amended application. The renewed excitement for its technology, and the support from investors, means that Dendreon will now dust off its ideas for applying it to other forms of cancer, like breast, colon, bladder, and kidney tumors, Gold said. The company plans to discuss those plans in greater detail at an analyst meeting in the summer, he said.

The company hasn’t disclosed what Provenge’s price will be, but it has said in the past that it will be comparable to other biotech drugs, meaning it will likely be tens of thousands of dollars per patient.

Gold had some philosophical moments on the conference call, as he took time to thank the company’s investors for supporting the many years of development for Provenge. “Today reminds us how the U.S. biotech industry can continue to innovate,” he said. “It could not have occurred without access to capital. Exploring new frontiers in medicine is costly and risky.”

As a reminder, Dendreon has worked all those years to develop its active immunotherapy, or cancer vaccine, technology. It doesn’t work like a traditional chemotherapy even a targeted antibody drug that’s supposed to seek out cancer cells and spare healthy ones. Instead, Provenge is designed to trigger the body’s natural immune defenses to recognize cancer cells as foreign invaders, like a virus, and kill them.

Dendreon’s approach requires blood to be drawn from a patient, and some white blood cells vital to the immune system, called dendritic cells, to be separated in a lab. The cells are shipped to the company and incubated with a genetically engineered protein found on prostate cancer cells, called PAP. This process is supposed to “teach” the immune system to recognize cells with this marker as foreign and fight them, and is sort of like waving a red flag in front of a bull. These newly revved-up white blood cells are shipped back in cold storage from the Dendreon factory to the clinic, and re-infused into the patient, giving them new ability to fight off the cancer.

Dendreon has generated loads of drama and controversy in its history. Many scientists thought its first bid for FDA approval in 2007 was premature on the basis of a study of 127 men, yet the company passed muster of an expert advisory committee by a 13-4 vote. Then the company was stunned when the FDA rejected the advice of its own committee in May 2007, saying it wanted to first see the results of this ongoing study of more than 500 men. You can read more about the whole saga in this recap we published on April 3.

Many investors have been betting, and hoping, that Dendreon would fail again. More than 19 million shares out of Dendreon’s 98 million shares outstanding were held in a short position at the end of March, according to Nasdaq data. Gold resisted whatever urge he might have for an in-your-face comment to his critics, but he took the opportunity make some very lofty comments.

“The most meaningful science is often the most controversial,” Gold said. He added, “It is my personal hope this will demonstrate the diagnosis of cancer is not hopeless.”

Author: Luke Timmerman

Luke is an award-winning journalist specializing in life sciences. He has served as national biotechnology editor for Xconomy and national biotechnology reporter for Bloomberg News. Luke got started covering life sciences at The Seattle Times, where he was the lead reporter on an investigation of doctors who leaked confidential information about clinical trials to investors. The story won the Scripps Howard National Journalism Award and several other national prizes. Luke holds a bachelor’s degree in journalism from the University of Wisconsin-Madison, and during the 2005-2006 academic year, he was a Knight Science Journalism Fellow at MIT.