On 26 November, Cassava Sciences, a clinical-stage biotechnology company focused on developing treatments for Alzheimer’s disease (AD), announced that its experimental drug, simufilam, did not meet its pre-specified co-primary, secondary and exploratory endpoints in the Phase 3 ReThink-ALZ study. The trial, which aimed to evaluate the safety and efficacy of simufilam in people with mild-to-moderate AD, was conducted across over 75 clinical sites in the US, Canada and Australia. The double-blind and placebo-controlled trial randomised 804 participants to receive either simufilam or a placebo twice daily for 52 weeks. The results revealed that simufilam did not show a significant reduction in cognitive or functional decline compared to the placebo group.
The co-primary endpoints were the change in cognition and function from baseline to the end of the double-blind treatment period at week 52, assessed by the ADAS-COG12 and ADCS-ADL scales. Additionally, secondary endpoints, which included well-established measures of neuropsychiatric symptoms and caregiver burden, also did not demonstrate significant improvements. Safety was evaluated through multiple measures, including adverse event monitoring. In response to these findings, Cassava Sciences also announced the discontinuation of the open label extension study and another Phase 3 trial, ReFocus-ALZ, both evaluating simufilam in mild-to-moderate AD.