DUBLIN – "Unexpected, early and bad" was how Andrea Pfeifer, CEO of AC Immune SA, characterized the news that its partner, Genentech Inc., was terminating two phase III trials of anti-amyloid beta (a-beta) antibody crenezumab in Alzheimer's disease, following an interim analysis, which suggested that neither study would reach its primary endpoint. The Lausanne, Switzerland-based company's stock (NASDAQ:ACIU) was off by 37 percent during premarket trading Wednesday but went into free fall once the market opened. It ended the day at $3.65, a drop of 66 percent on its previous close.