Some called it the cure. An experimental drug known as GDNF had actually reversed the effects of Parkinson's disease in rats and monkeys. Fifty brave patients volunteered to have holes drilled through their skulls and GDNF pumped into their brains. The clinical trial results were stunning: men and women once thought to be beyond hope leapt back into normal life. They could walk, run, smell, taste, and make love once again.

It all came to an abrupt halt when Amgen, Inc. cut the GDNF trials short in the fall of 2004. The company said it had found disturbing side effects in monkeys, but the danger to humans was unclear. Amgen's decision started a race against the clock, as patients battled the corporation for access to GDNF – even as their previous symptoms began to return. In Monkeys in the Middle, investigative reporter Nick Nelson recounts the true story of the patients who took on the world's biggest biotechnology company for the right to be kept alive.