Annovis Bio Inc. presented new clinical efficacy and biomarker data from two phase II studies of its lead candidate, ANVS-401 (posiphen), at the 2021 Alzheimer's Association International Conference (AAIC) that saw the stock sink soon afterward. The Berwyn, Pa.-based company’s shares (NYSE:ANVS) took a powerful hit as shares had plunged a dramatic 60% to close at $43.50 each on July 29.