SEATTLE (AP) -- Biotechnology company Dendreon Corp. said Friday the Food and Drug Administration will make a regulatory decision on the potential prostate cancer vaccine Provenge by May 1.

The drug is aimed at treating prostate cancer. It works as a vaccine to stimulate the body's immune system so it fights the cancer, but is given as a treatment rather than a preventive.

Shares of Dendreon fell 4 cents to $28.01 in morning trading.