Not depressed yet

If history is any guide, there's no reason to think the failure of Targacept Inc. and AstraZeneca plc's first flexible-dose Phase III trial of TC-5214 automatically means the program is dead. However, the partners probably will have to succeed in two of the remaining three depression trials to have a shot at approval. Two of those are fixed-dose studies - which some data suggest are less likely than flexible-dose studies to succeed.

Even among drugs that prove to be effective, subjective entry criteria and endpoints plus high placebo response rates in major depressive disorder (MDD) trials lead to high failure rates...