A blister pack containing Pfizer's Neurontin 400mg tablets, produced by Pfizer Inc., are arranged for a photograph in London, U.K., on Friday, May 2, 2014. AstraZeneca Plc rejected Pfizer Inc.'s sweetened takeover proposal, saying the 63.1 billion-pound ($106.5 billion) offer fails to recognize the value of the promising experimental medicines under development by the U.K.'s second-biggest drugmaker. Photographer: Chris Ratcliffe/Bloomberg via Getty Images
