Unfortunately, wasa, yes to your first question. Prana has...

Unfortunately, wasa, yes to your first question. Prana has positive biomarker results from a phase 2A trial. Patients did not experience clinically meaningful improvement ( don't start on me here, Skint.....).
It's a big bet for big pharma to invest $300m on the basis of this, esp. With the clock winding down to completion for other putatively disease
modifying studies already in phase 3 (lilly's solenuzemab trial , 2000 patients due for completion July 2012).
Prana need to force pharma's hand by laying more compelling clinical data on the table asap, and a definitivee phase 2 with 2-300 patients is the only
means they have to this end with the cash they have at hand.

Phase 3's are so big and expensive because they have to satisfy FDA standards as a key step to drug registration. The cynic in me might argue that this in itself is designed by big pharma to ensure small players Ned to partner up with them in order to get in the game....