Simufilam is an experimental drug for Alzheimer’s disease that has improved patients’ ability to think and function. The drug is taken orally, as a 100 mg pill, and targets a protein in the brain called filamin A. The Texas-based drugmaker Cassava Sciences says Simufilam has been shown in studies to improve cognition and reduce dementia-related anxiety, aggression and delusions.
There is no cure for Alzheimer’s, but medications can help manage symptoms and slow the disease’s progression as it moves from early to middle and late stages. Unfortunately, new pharmaceuticals to treat Alzheimer’s disease and related dementias are rare, though 2021 did see the FDA approval of Aducanumab/Aduhelm in 2021 (see Differences below).
Simufilam has very recently begun a large Stage 3 trial, and it may become available in the next few years if positive results can be repeated on a larger scale.
Simufilam is designed to restore filamin A proteins in the brain to their normal shape and function.
Filamin A proteins have several roles, and are considered a “scaffolding protein” that help brain cells communicate. When these proteins (also known as FLNA) are not functioning correctly, it can lead to neurodegeneration and neuroinflammation, which means the destruction of brain cells that leads to Alzheimer’s disease.
Most pharmaceuticals for Alzheimer’s disease have been designed to target a different protein called amyloid beta, which forms clumps or tangles in the brains of people with certain kinds of dementia including Alzheimer’s. 2021 saw the FDA approving the first medication for Alzheimer’s in more than 17 years, a drug called Aducanumab (brand name Aduhelm) that targets amyloid beta. Several others are in the works.
Filamin A, the protein strengthened by Simufilam, has been less prominent than amyloid in the science of understanding and treating dementia, but studies are showing that it may be possible to slow the progression of Alzheimer’s disease and even increase thinking ability by taking the drug.
Cassava Sciences released results from studies showing that Simufilam improved thinking ability for people with mild to moderate Alzheimer’s disease, with no adverse side effects. And while Alzheimer’s is a progressive disease, meaning it gets worse over time, two-thirds of the participants in a study (funded by the National Institutes of Health) actually improved their scores in tests meant to rate their level of cognition after nine months on the drug. And about 22% of participants saw their scores decline less than normal.
Simufilam also reduced typical dementia-related behaviors, including anxiety, depression and delusions. At the beginning of the Cassava study, 66% of participants reported dealing with these issues, while that number dropped to 50% at the end of the study.
Biomarkers for Alzheimer’s disease also improved. Biomarkers are protein clumps and tangles that can be found in the spinal fluid of people with dementia, and after nine months on Simufilam those biomarkers were reduced.
The results described on this page came from Cassava Sciences’ open-label study of Simufilam, in which about 150 people with Alzheimer’s at various stages participated. The next step is Stage 3 trials on a much larger scale, with more than 1,000 participants and placebo control (meaning some people will be given a pill that does nothing to see if their results are different).
Trials of Simufilam are underway in Florida, Texas, Ohio, Nebraska, Arizona, New Jersey, and California. It may still be possible to sign up to be part of the trial. Click here for contacts of study coordinators.
Critics of Simufilam have said that the drug studies so far are too small-scale to demonstrate effectiveness. The larger Stage 3 trials, beginning at the end of 2021, address this concern and move Simufilam closer to becoming available to the public.
We don’t know yet when Simufilam will become available, as it’s possible it could receive a “Breakthrough Therapy” designation from the FDA that would speed the process. Results through the Phase 3 trials would need to remain strong as the drug is tested on hundreds of subjects and compared against placebo.
FDA approval for Simufilam by the end of 2022 is possible, but sometime over 2023 or 2024 is more likely, if the trials go well.
How much Simufilam will cost is not yet known. Whether private insurers, Medicaid and/or Medicare will cover the drug won’t be determined until after FDA approval.