Dendreon, With Key Milestone Now Reached, Sees Final Results on Immune-Boosting Drug Coming in April

Dendreon-watchers, mark your calendars for April. The Seattle-based biotech company (NASDAQ: [[ticker:DNDN]]) said today its study of 500 men with terminal prostate cancer will offer a final answer by April on whether its experimental immune-boosting drug helps patients live longer.

The trial, known as Impact, enrolled men with terminal forms of prostate cancer and randomly assigned them to take Dendreon’s sipuleucel-T (Provenge) or a placebo. The study was designed so that a statistically valid survival comparison of the two groups could be done after at least 304 men died, and that necessary number of deaths has now been met, said Dendreon CEO Mitchell Gold made the announcement today at the JP Morgan Healthcare Conference in San Francisco. Patients who entered the study were seriously ill, having already developed resistance to the standard testosterone-blocking therapy, and had a life expectancy of 18 to 20 months, Gold said.

It’s impossible to read the tea leaves on the timing of this announcement, and whether it bodes well or ill for Dendreon, because the company is still blinded to the comparison of the two groups of patients. This analysis is critical for the company, because it has been waiting for this answer since May 2007, when the FDA stalled its application to market the product in the U.S. Dendreon had argued that its drug, which is meant to provoke the immune system to fight cancer cells like a virus, ought to be approved on the basis of a smaller study of 127 men, which suggested that it could prolong lives by a median of 4.5 months, with minimal side effects.

An FDA advisory panel agreed with the company in March 2007, raising the hopes of investors and patients. But the FDA ultimately decided it wanted more proof from this ongoing trial of 500 more men, that the earlier finding wasn’t a statistical fluke. Obviously, a lot is riding on the study, since prostate cancer kills an estimated 27,000 men each year in the U.S., according to the American Cancer Society.

Dendreon’s Gold sounded optimistic that he will soon be able to offer a new, milder alternative to the dreaded chemical castration and toxic chemotherapy.

“This is a very exciting time for us, and for patients,” Gold said at the conference. He later used a football analogy to describe the company’s situation. “We’re on the 10-yard line, we’re in the red zone, and we’ve got to punch it in to the end zone now.”

Dendreon took an early peek at the Impact study back in October, which suggested it is within hailing distance of being successful. The study must show the Dendreon drug lowers the risk of death by at least 22 percent, and the interim analysis after two years of following patients showed that the product lowered the risk of death by 20 percent. That finding is on track with what previous clinical trials have shown, which makes Dendreon optimistic that the benefit of the drug will become even clearer over time, essentially as more placebo patients die.

The company has been focused on sipuleucel-T for years, although lately it has started to emphasize that it isn’t putting all its eggs in that one basket. Dendreon is applying its same technology to treating women with breast cancer who carry a mutated form of the Her-2 gene. Dendreon also has a more conventional oral pill it has developed for cancer, D-3263, which is being prepared to enter its first clinical trial, Gold says.

The company had about $108 million in cash and investments at the end of the year, Gold says. That dollar amount is always important for a company that doesn’t have any marketed products yet to sell, and it will be an extra important lifeline for Dendreon if the final analysis of the Impact study turns up negative in April.

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.