What about the reports of high blood pressure and clots?
From March 2007:
And although Provenge was found to be "relatively well-tolerated" overall, with chills, fatigue and back pain as the most common side effects, the FDA expressed concern that patients treated with the drug showed a higher rate of cerebral vascular accidents, or strokes -- 3.9% vs. 2.6% in patients given a placebo.
Strokes and other brain-related problems were no more common with Provenge -- a worry raised by earlier studies. However, four men given Provenge suffered lung clots, though none were fatal. High blood pressure was twice as common with Provenge. Overall, the rate of serious side effects was the same in each group.