Dendreon Preview: Drama Could Culminate in the First Cancer Vaccine Approval

Last Updated Apr 22, 2010 1:22 PM EDT

DNDN Provenge soap operaNext week brings the highly anticipated FDA decision on the approval of Dendreon's (DNDN) prostate cancer vaccine Provenge (sipuleucel-T).

Most analysts expect the drug to be approved -- and to achieve blockbuster status within the next few years. But Dendreon's ride to the top has been anything but smooth, delivering more drama than daytime television. Themes from the company's contentious history include:

  • The Cancer Vaccine Stigma: The cancer vaccine field suffered so many failures that investors would run for the hills at its mere mention, forcing the remaining biotechs in the space to collectively re-brand themselves as "specific active immunotherapy" companies. The late-stage trial graveyard includes Antigenics, BioVest, CancerVax, Cell Genesys, Favrille, Genitope, Progenics, Therion... and Dendreon itself (see next bullet).
  • The Pivotal Trials: Dendreon's first two Phase III Provenge trials missed their primary endpoint of time to progression but showed a survival benefit in post-hoc analyses. The company filed for approval anyway, arguing that survival was the most important measure, and an FDA advisory committee agreed. But the agency rejected the drug (see next bullet) until a third Phase III trial designed to show survival turned out positive two years later.
  • The Conspiracy Theory: Some Dendreon fans have argued that politics and conflicts of interest at the FDA blocked Provenge's approval the first time around. And the SEC is currently investigating an alleged short-selling scandal that caused Dendreon's stock to tank 65 percent in 75 seconds just before the release of the final Phase III data.
  • The Credibility Issue: Dendreon execs have raised some eyebrows by selling off chunks of stock, once right before the first FDA rejection and again last year.
  • The Commercial Questions: The champagne corks had barely popped on the successful Phase III trial when analysts started raising questions about the magnitude of benefit, the challenges of manufacturing a personalized vaccine, and potential pricing/reimbursement issues.
With all that drama, it's easy to lose focus of one of the most important parts of Dendreon's story: Provenge has the potential to be the first therapeutic cancer vaccine ever approved by the FDA. The concept of using a vaccine to stimulate the body's immune system to fight cancer has been a Holy Grail of oncology research for decades. Provenge is by no means a cure -- but it extends survival a few months, and since vaccines don't have the nasty side effects of typical cancer drugs, they are likely to be combined with other life-extending drugs. Combine enough of them, and maybe we can finally turn cancer into a chronic disease.

Soap Opera photo by Flickr user Mike Licht, NotionsCapital.com, CC.

  • Trista Morrison

    Trista Morrison is a staff writer at BioWorld Today, a daily newspaper that