An experimental treatment that takes an entirely new approach to fighting prostate cancer extended survival in a late-stage study, its maker announced Tuesday.

Seattle-based Dendreon Corp. said that its Provenge cancer vaccine improved overall survival when compared to a dummy treatment in a study of 512 men with advanced disease.

No survival details or information on side effects were given. Full results will be presented at an American Urological Association meeting later this month, and Dendreon said it would seek federal approval of the treatment later this year.

Provenge is not like traditional vaccines that prevent disease. It’s a so-called therapeutic vaccine that treats cancer by training the immune system to fight tumors. If approved, Provenge would be the first such treatment on the market.

This is the second major study in which Provenge has shown a survival benefit, leading some scientists to hope not just for its approval but for a new approach to fighting cancer beyond the surgery, radiation, hormones and chemotherapy used now.