By Phase III, researchers are supposed to have a pretty good handle on just how promising an experimental therapy can be. There's proof-of-concept data in the can and some clear indications of just how big a market a new drug can go on to capture.
But even if the odds of success are somewhat better, the risk for losing big is greater as well. A pharma company often steps in to nail down a licensing deal, but late-stage trials typically require large patient populations and consume enormous budgets.
This year's worst Phase III losers are prime examples of just what can go wrong. From Alzheimer's to cancer, investigators are forced time and again to bet on drugs that target mysterious disease triggers.
Late-stage drug development always requires being prepared for the kind of catastrophic failure that can damage big pharma companies and utterly destroy a smaller outfit. Every Phase III trial represents a throw of the dice, here's a look at some of the top programs that rolled snake eyes in 2010.