Shares of Cortexyme Inc. CRTX, -75.16% tumbled 72.7% in trading on Wednesday, the day after the company said a late-stage clinical trial evaluating its experimental Alzheimer’s disease treatment failed to meet the study’s endpoints. Cortexyme’s stock is down 43.3% this year; the S&P 500 SPX, 0.11% is up 21.8%.