 Shares of Cassava Sciences Inc. SAVA, 0.14 plunged 24.2 in premarket trading on Wednesday after Reuters reported that the Justice Department is investigating whether the company manipulated clinical data for a still-investigational Alzheimers disease drug, citing people familiar with the matter. Cassava put out a news release in December that said a scientific journal did not find evidence of manipulated data in a 2005 paper authored by the companys scientists after short sellers alleged data manipulation in some previously published research. 