Cassava Sciences has given up on simufilam in Alzheimer’s disease. Months after seeing one phase 3 trial fail, the biotech is planning to stop development altogether after chalking up another late-stage flop.
Texas-based Cassava discontinued the second study, ReFocus-ALZ, when it reported the first failure late last year. But with all the patients completing 52 weeks of follow-up, and many making it to the 76-week assessments, before Cassava pulled the plug, ReFocus-ALZ still offered the biotech a final chance to show simufilam may be effective against Alzheimer’s.
Instead, the failure of the trial sealed simufilam’s fate. Cassava said ReFocus-ALZ missed its prespecified co-primary, secondary and exploratory biomarker endpoints. The co-primary endpoint data left no room for optimistic interpretations.
On ADAS-COG12, where lower numbers mean less cognitive impairment, scores rose by 4.97 and 5.26 points in the two simufilam cohorts and by 4.70 points in the placebo group. Similarly, on ADCS-ADL, where higher numbers mean less functional impairment, scores fell by 6.27 and 6.43 points on simufilam arms and by 5.32 points on placebo.
The failures on the co-primary endpoints and broader dataset led Cassava CEO Rick Barry to conclude the trial “showed no treatment benefit for patients.” Barry was blunt about the data and the next steps.
“These results were unambiguous,” Barry said. “Cassava will discontinue all efforts to develop simufilam for Alzheimer’s disease and we expect to phase out the program by the end of Q2 2025.”
Having recently entered a license agreement, Cassava has begun preclinical studies to assess simufilam as a potential treatment of tuberous sclerosis complex-related epilepsy. While the biotech is investing in those studies, it is maintaining its “ongoing strategic expense management efforts,” Barry said. Cassava ended last year with $128.6 million in cash and cash equivalents.
Shares in Cassava fell more than 20% to $2.20 when the markets opened Tuesday from a Monday closing price of $2.78.