(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.

Cassava Sciences has revealed the late-stage clinical failure of controversial Alzheimer’s drug simulfilam. The company had pledged to share the results whether “good, bad or ambiguous.”