(Reuters) -Cassava Sciences said it will stop all trials of its Alzheimer's disease drug after it failed a late-stage study, sending shares of the drug developer plummeting 83% in early trading on Monday.

The Cassava Sciences story ended Monday exactly as many knew it would — with the company’s experimental drug for Alzheimer’s disease, simufilam, failing a clinical trial.

(Reuters) -Cassava Sciences on Monday said its experimental Alzheimer's disease drug did not meet the main or secondary goals in a late-stage study. The treatment, simufilam, failed to demonstrate a significant reduction in cognitive or functional decline compared to a placebo in patients with mild-to-moderate Alzheimer's disease,

Cassava Sciences stock collapsed after an Alzheimer’s drug the company was testing failed to significantly help participants in a clinical trial. The stock plummeted 84% to $4.15 Monday after reporting that a Phase 3 trial meant to demonstrate the efficacy of a medication called Simufilam fell short of key milestones.

Following the ReThink study failure, Cassava Sciences is discontinuing the Phase III ReFocus trial and open-label study.