Study results positive for new cancer drug therapy for prostate patients.

Byline: Luke Timmerman

Feb. 17--Dendreon, a Seattle biotechnology company, has found in a small study that its experimental therapy can significantly extend lives of prostate-cancer patients who have failed on standard treatments.

It marks the first time in decades of research that a final-stage, placebo-controlled experiment has shown a cancer treatment can substantially prolong life by revving up the body's immune system.

Though the result appears promising, it comes with some caveats, outside experts said.

Dendreon found in a 127-patient study that after three years, 34 percent of patients were still alive after taking its Provenge treatment, compared with 11 percent on placebo. Half the Provenge patients were alive after 25.9 months, while half the patients on placebo survived 21.4 months or more.

The side effects with Provenge…