Key TakeawaysAbbVie said it would take a $3.5 billion dollar impairment charge related to the failure of a drug it acquired in its purchase of Cerevel Therapeutics.The biotech company reported in November that the schizophrenia drug, emraclidine, didn't reach primary endpoints in a Phase 2 trial.Abbvie explained that following the study, it began an evaluation of the impact of the results, "which resulted in a significant decrease in the estimated future cash flows for the product." AbbVie (ABBV) shares fel ...