The effect clinical trial results can have on a pharma company’s stock are tremendous and can work both ways. Disappoint investors and a sharp descent for the shares is likely. Conversely, release encouraging news, and the sky’s the limit. It is safe to say that in the case of Cassava Sciences (SAVA), investors were very happy following its latest news release. Cassava shares are up nearly 190% (at one point, the stock was up over 490%) this week, after the company disclosed encouraging interim data from an open-label study of its Alzheimer’s disease candidate simufilam.