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

[[Updated]] Dendreon has been vindicated. The Seattle biotech company, after living through years of controversy about whether its experimental drug helps prostate cancer patients live longer, said today that a clinical trial of 512 men now shows that the treatment can help prolong life with minimal side effects. Shares skyrocketed by more than $12, rising above $20 a share after the opening bell.

The trial, called Impact, randomly assigned men to get either the company’s experimental immune-boosting therapy, Provenge, or a placebo. The study found that men who took Provenge had a lower risk of death than those in the control group—the company needed to show at least a 22 percent improvement on that measure. Side effects were consistent with what was seen in previous trials—fever and chills that lasted a couple days. Dendreon (NASDAQ: [[ticker:DNDN]]) will now pull together this new information to update its application with the FDA in the fourth quarter, in the hopes of bringing this new drug to the U.S. market. Full data are expected to be announced at 2:20 pm Central time on April 28 at the American Urological Association meeting in Chicago.

The finding is a watershed moment for the field of cancer immunotherapy, sometimes called cancer vaccines, in which researchers try to stimulate the immune system to fight cancer cells like a virus. If Dendreon can win FDA approval, it will be the first company in this field to do so, after a long list of failures from the past couple of years, at companies like Cell Genesys, Favrille, and Genitope. Dendreon’s new drug will offer a new treatment option for about 30,000 men who die in the U.S. each year from prostate cancer, beyond the standard hormone deprivation and chemotherapy, which have side effects many men want to avoid. It is also a breakthrough moment for the Seattle biotech cluster and for Dendreon. The company was founded in 1992, has spent more than $560 million of investors’ money on R&D, and hopes to make Provenge its first marketed product in the U.S.

“Today is a historic day for patients, our industry, the scientific community, and certainly for Dendreon,” said CEO Mitchell Gold, on a conference call this morning with analysts. In a statement, he added, “The successful outcome from the Phase 3 Impact study provides validation of the long-pursued goal of harnessing the human immune system against a patient’s own cancer.”

Dendreon didn’t provide specifics about the trial outcome in today’s release, such as the magnitude of the survival benefit, or the degree of statistical significance of the finding, which measures how confident statisticians are that the finding isn’t a fluke.

Dendreon offered a few hints about how strong the result was on the conference call this morning. Provenge’s ability to prolong lives

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.