Friday's Health Winners & Losers

Updated from 12:13 p.m. EDT

Dendreon (DNDN Quote) shares soared 147.7% Friday after the Food and Drug Administration said the company's prostate cancer vaccine treatment, Provenge, was safe and effective in treating the disease. A final decision from the FDA is expected on May 15. Shares of Dendreon rose $7.71 to $12.93.

Shares of Medarex (MEDX Quote) also are on the rise. The company said late Thursday that its Valortim drug was effective in the treatment and prevention of anthrax infections when tested on monkeys. The stock closed up $1.45, or 12.6%, to $12.94.

On the flip side, Acadia Pharmaceuticals (ACAD Quote) and AtheroGenics (AGIX Quote), both of which have fluctuated greatly in price over the previous two weeks, moved lower over the course of the day. Acadia fell 9% to close at $15.02. AtheroGenics shed 3.2% to $2.71 in earlier trading but closed up slightly for the day at $2.81. ...