Dendreon Makes History: FDA Approves First Active Immune-Booster to Fight Cancer

[Updated: 11:05 am Pacific] Scientists have been dreaming for a century about therapies that actively harness the power of the body’s immune system to kill cancer cells like an invading virus or bacteria. Today, Seattle-based Dendreon has made history by winning the first-ever FDA approval for this kind of cancer-fighter. Shares climbed 15 percent to $45.50 after the news broke.

The good news for Dendreon (NASDAQ: [[ticker:DNDN]]) came today when it received clearance from the FDA to start selling sipuleucel-T (Provenge) to men in the U.S. with terminal prostate cancer that has spread, even after prior rounds of standard hormone-deprivation therapy, according to a statement on the FDA website. The agency gave the green light after Dendreon showed in a trial of 512 men that patients lived a median time of 25.8 months if they got Provenge, compared to 21.7 months for those on a placebo. Patients on the drug had minimal side effects of fever and chills that lasted a couple days.

The FDA’s decision will have far-reaching impact for years. The drug is the first marketed product for Dendreon, which has piled up a deficit of more than $700 million in its 18-year development quest. The product is forecasted by analysts to exceed $1 billion in U.S. sales after a couple years on the market. Dendreon could morph into the regional anchor Seattle’s biotech community has lacked since Immunex was acquired by Amgen in 2002. For the 27,000 men in the U.S. who die each year from prostate cancer, the drug represents some hope for a longer life, and a higher quality of life alternative to chemotherapy. And for researchers, it offers new possibilities for a mode of treatment beyond surgery, chemotherapy, radiation, and targeted biotech pills and antibodies that must be taken chronically.

“This is a huge advance,” said Dr. John Corman, a urologist at Virginia Mason Medical Center in Seattle, and an investigator in Provenge clinical trials for eight years. “This is the first immunotherapy agent that’s been shown to provide a survival benefit for prostate cancer patients. And it’s a completely new class of therapy that provides remarkable opportunities for R&D.”

[Update with company statement.] Dendreon said the drug will be made available initially at about 50 medical centers in the U.S. The company didn’t say in its statement today how much it will charge for the drug, although it plans to hold a conference call with analysts and investors at 2:30 pm Eastern/11:30 am Pacific.

“The approval of Provenge is a significant step towards realizing our mission of transforming the lives of patients with cancer, and it also marks Dendreon’s transformation into a commercial enterprise,” CEO Mitchell Gold said in the statement.

While today’s FDA approval is groundbreaking, it’s worth being precise about what this means, and what it doesn’t. Treatments like Dendreon’s are most accurately referred to as “active immunotherapies,” although scientists sometimes loosely call them “cancer vaccines” in the media. Just to be clear, Dendreon’s product is a treatment that people get after they’ve already been diagnosed with prostate cancer, so it isn’t a vaccine in the traditional sense that prevents people from getting a disease. Because Dendreon’s treatment “teaches” the immune system to recognize certain cancer cells and fight them on its own, for months or even years, it’s considered an “active” immunotherapy. That’s also different from what researchers sometimes call “passive” immunotherapy. It’s fair to consider an intravenous-delivered antibody drug, like Roche’s rituximab (Rituxan), a “passive” immunotherapy because it works in part by stimulating the immune system to fight cancer cells, at least while the drug is active in the blood. It’s also fair to call Merck’s human papillomavirus vaccine (Gardasil) a cancer vaccine, because it prevents women from getting infected with a virus known to cause cervical cancer.

Whatever you choose to call Provenge, the anticipation of today’s FDA approval has already transformed Dendreon. A few weeks before the defining clinical trial data arrived in April 2009, the company’s stock was trading around $2, cash was running low, and it had about 200 employees. After the data arrived and was presented at a urology meeting in Chicago, Dendreon raised $630 million from investors, announced plans to grow to 600 employees, added two more drug factories, and saw its stock climb to more than $40 a share.

Plenty of questions remain about

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.