Cassava Sciences said that its drug did not significantly reduce cognitive decline in 1,900 people with mild to moderate Alzheimer’s disease.

(Reuters) -Cassava Sciences said on Monday 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 more than 80% before the bell.

Cassava Sciences Inc.’s stock crated 85% in premarket trade Monday, after the clinical-stage biotech said a trial of a treatment for mild-to-moderate Alzheimer’s disease failed to meet its main goals.

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.

Cassava Sciences Inc. ($SAVA) saw its stock plummet over 80% pre-market on Monday following the failure of a pivotal Phase 3 trial for its Alzheimer’s disease drug, simufilam. Trading was briefly halted earlier as the company revealed that the trial did not meet its primary endpoints for improving cognitive or functional decline at week 52,