Cassava Announces Publication of Peer-Reviewed Phase 3 Results for Simufilam in Alzheimer’s Disease in the Journal of Prevention of Alzheimer’s Disease
As previously disclosed, the studies did not meet pre-specified co-primary, secondary, or exploratory biomarker endpoints
The paper provides a detailed analysis of the RETHINK-ALZ and REFOCUS-ALZ studies and confirms simufilam’s favorable safety profile in these studies
Exploratory post-hoc analyses offer informative insights
Topline results of RETHINK-ALZ (NCT04994483), which randomized 804 people with mild to moderate Alzheimer’s disease, were originally reported in
“In keeping with our commitment to report the detailed results, we are pleased to make the data from the RETHINK-ALZ and REFOCUS-ALZ studies available to the Alzheimer’s disease scientific community through publication in the highly respected
Exploratory Findings
Although the trials failed to meet their co-primary, secondary, and exploratory biomarker endpoints, some prespecified secondary endpoints and post hoc hypothesis-generating analyses showed potential treatment differences between the higher dose of simufilam and placebo in the predefined mild subgroup (mini-mental state exam (MMSE) score 21-27) on the 12-item Alzheimer’s Disease Assessment Scale – Cognitive Subscale (ADAS-Cog12), including:
- Mild Patients in REFOCUS-ALZ: Simufilam (100 mg) was associated with slower cognitive decline than placebo in the prespecified mild subgroup, with differences at Week 4 and Weeks 28, 40, 52, and 64 (nominally significant at p = 0.01, 0.01, 0.02, 0.02, and 0.02, respectively). This potential treatment difference did not replicate in RETHINK-ALZ and was no longer evident at Week 76 of REFOCUS-ALZ (which had 45% missing data due to early study termination).
- Pooled Mild Patients in REFOCUS-ALZ and RETHINK-ALZ: A prespecified pooled analysis of mild patients administered simufilam (100 mg) or placebo in both trials through week 52 showed potential treatment group differences at weeks 4 and 28 (nominally significant at p < 0.01). An exploratory post hoc analysis of the pooled mild subgroups using a plasma p-tau181 cutoff of ≥ 67 (the highest half of all patients) showed a difference in the slowing of decline at Weeks 4, 28, and 40 (nominally significant at p = 0.03, 0.001, 0.006, respectively), with a trend at Week 52 (p = 0.066).
These clinical trials were the first Phase 3 Alzheimer’s disease studies to rely primarily on a plasma biomarker (p-tau181) for biological confirmation of disease. The authors of the paper observed that an amyloid PET (positron emission tomography) sub-study in REFOCUS-ALZ showed that 21% of participants (33 of 160) were unexpectedly amyloid negative at baseline, indicating an absence of Alzheimer’s disease pathology. This suggests that the plasma p-tau181 assay cut-off used as an entry criterion in both trials was insufficient to screen effectively for Alzheimer’s disease pathology in trial participants.
Dr. Anton Porsteinsson, Director of the University of Rochester’s Alzheimer’s
Overview of the RETHINK-ALZ and REFOCUS-ALZ Studies
The Phase 3 RETHINK-ALZ (NCT04994483) and REFOCUS-ALZ (NCT05026177) trials were designed as multi-center, double-blinded, placebo-controlled, randomized parallel group studies to evaluate the safety and efficacy of simufilam compared to placebo across distinct clinical sites in the U.S., Canada, and
The prespecified co-primary endpoints for the studies included the change in cognition and function from baseline to the end of the double-blind treatment period, assessed by the ADAS-Cog12 and ADCS-ADL scales, comparing simufilam to placebo. Secondary endpoints included several well validated measures of neuropsychiatric symptoms and caregiver burden. Safety was evaluated by adverse event monitoring, as well as standard laboratory and ECG assessments. REFOCUS-ALZ also included an evaluation of changes in plasma and cerebrospinal fluid biomarkers as well as an evaluation of MRI and PET scans.
About Simufilam
Simufilam is a proprietary, investigational oral small molecule believed to modulate activity of the filamin A protein, which regulates diverse aspects of neuronal development1.
About Cassava Sciences, Inc.
For more information, please visit: https://www.CassavaSciences.com
References:
- Zhang L, Bartley CM, Gong X, Hsieh, LS.; LinTV, Feliciano DM, Bordey A. "MEK-ERK1/2-Dependent FLNA Overexpression Promotes Abnormal Dendritic Patterning in Tuberous Sclerosis Independent of mTOR. Neuron (2014) 84 (1), 78-91. DOI: 10.1016/j.neuron.2014.09.009
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Cautionary Note Regarding Forward-Looking Statements: add a few notes on the paper
This news release contains forward-looking statements that may include but are not limited to statements regarding the implications of safety observations in the REFOCUS-ALZ and RETHINK-ALZ studies for the Company’s ongoing development program in TSC-related epilepsy and the potential for the observations in the published paper to contribute to Alzheimer’s disease research. Forward-looking statements may be identified by words such as “anticipate”, “before”, “believe”, “could”, “expect”, “forecast”, “intend”, “may”, ”pending”, “plan”, “possible”, “potential”, “prepares for”, “will”, and other words and terms of similar meaning.
Such statements are based on our current expectations and projections about future events. Such statements speak only as of the date of this news release and are subject to a number of risks, uncertainties and assumptions, including, but not limited to, those risks inherent in drug discovery and development or specific to Cassava Sciences, Inc., as described in the section entitled “Risk Factors” in our Annual Report on Form 10-K for the year ended December 31, 2024 and Quarterly Report on Form 10-Q for the period ended
All of our pharmaceutical assets under development are investigational product candidates. These have not been approved for use in any medical indication by any regulatory authority in any jurisdiction and their safety, efficacy or other desirable attributes, if any, have not been established in any patient population. Consequently, none of our product candidates is approved or available for sale anywhere in the world.
Our clinical results from earlier-stage clinical trials or preclinical studies may not be indicative of future results from later-stage or larger scale clinical trials and do not ensure regulatory approval. You should not place undue reliance on these statements or any scientific data we present or publish.
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