Some said it a miracle drug; others called it the cure. A drug knowns simply as "GDNF" seemed to do the impossible by actually reversing the effects of Parkinson's disease. The miracle ended in the fall of 2004 when Amgen Inc. abruptly halted clinical trials of GDNF and denied access to the drug. In "Monkeys in the Middle," investigative reporter Nick Nelson recounts the true story of the brave patients who took on the world's biggest biotechnology company for the right to be kept alive.