Cassava’s Alzheimer’s drug fails in final-stage trials, stock plunges

Cassava Sciences has announced that its experimental drug for Alzheimer's disease, simufilam, did not meet either its primary or secondary objectives in a crucial late-stage study. The company confirmed on Monday that the treatment showed no significant reduction in cognitive or functional decline compared to a placebo in patients with mild-to-moderate Alzheimer's disease.

Following the disappointing results, Cassava stated it would halt a second late-stage trial of simufilam, as well as its open-label study. The news caused the company’s stock to plummet nearly 5% in premarket trading.

Despite the setback, the Austin-based firm indicated it would still present the trial data at an upcoming medical meeting. A conference call with analysts is also scheduled for 8 a.m. Eastern Time.

The Phase 3 trial aimed to assess simufilam’s ability to treat cognitive or functional decline in Alzheimer's patients compared to a placebo. However, the results at week 52 showed no significant improvement, based on two critical assessment scales—the DAS-COG12 and ADCS-ADL—measuring a patient’s ability to perform various tasks.

Although the drug failed to meet the study’s objectives, Cassava emphasized that simufilam maintained a generally favourable safety profile. "We took careful measures to enroll patients with mild-to-moderate AD," said CEO Rick Barry in prepared remarks. "Despite that, the loss of cognition in the placebo group was less pronounced than previously reported in other placebo-controlled studies in AD. We are working to understand this better."

As a result of the trial outcome, Cassava has decided to discontinue its second Phase 3 study. However, Barry confirmed the company would share more detailed analyses of both studies at a later date.