Cassava Faces Renewed Speculation Over Experimental Alzheimer’s Drug

Shares of Cassava Sciences plunged Tuesday in premarket trading after multiple Alzheimer’s researchers raised new concerns about the company’s experimental Alzheimer’s treatment, simufilam.

Company stakeholders have rushed to sell off shares of the Texas-based company following a New York Times article that highlighted a retraction of multiple papers authored by H.Y. Wang, an adviser to the company. The Times reported that PLoS One pulled five papers authored by Wang after an in-depth investigation revealed “serious concerns about the integrity and reliability of the results.” Two of those papers, which were co-authored by Lindsay H. Burns, senior vice president of neuroscience at Cassava, related to a protein in the brain that simufilam is designed to target.

The pulled papers have led other journals to flag other papers authored by Wang with “expressions of concern,” which raise questions about accuracy of data. The Times noted that those other journals, including Neurobiology of Aging, did not find evidence of data manipulation but listed methodological errors.

Cassava’s Chief Executive Officer Remi Barbier dismissed the concerns raised by the scientific community, referring to them as “bad actors” who have a financial interest in seeing the company fail. He said the “effort to besmirch Cassava appears endless,” the Times reported.

The concerns over the article withdrawals come in the wake of questions raised about Cassava’s research methods. Last year, two neuroscientists claimed that Cassava’s research included published images that appeared to have been manipulated using Photoshop or a similar type of software. The two researchers went on to short the company’s stock and also filed a Citizen’s Petition with the U.S. Food and Drug Administration that aimed to suspend Cassava’s clinical research into simufilam. That petition was denied earlier this year after the journal Neuroscience said it could find no evidence of data manipulation in Cassava papers published within its pages.

Simufilam is an oral small molecule drug candidate that is designed to restore the normal shape and function of altered filamin A (FLNA) protein in the brain. When FLNA is altered, it disrupts the normal operation of neurons, leading to Alzheimer’s pathology, neurodegeneration and neuroinflammation. Simufilam is currently being assessed by Cassava in two Phase III studies.

Neuroscientists have questioned this approach. Nobel Laurette Thomas Sudhoff told the Times that Cassava’s conclusions regarding FLNA are “not in the mainstream” and seem to him “implausible and contrived.”

Cassava has also been under investigation by the U.S. Securities and Exchange Commission regarding the data claim allegations.

As Cassava moves forward in its Alzheimer’s research, the company will continue to remain under scrutiny, particularly in the wake of the fallout over Biogen’s controversial Alzheimer’s drug, Aduhelm, which recently saw the Centers for Medicare and Medicaid Services limit the coverage of the medication to those Alzheimer’s patients who are part of an ongoing clinical trial.

Cassava’s leadership is well-aware of the regulatory shift in the Alzheimer’s landscape. Last month, the company warned that the FDA might place a clinical hold on simufilam due to holds placed on other experimental treatments for the form of dementia. In a filing with the SEC, the company said the concerns over Alzheimer’s treatments that have been hit with holds or had questions raised about the safety and efficacy, could impact the potential market share of the drug, even if it is ultimately approved by the FDA.

Cassava’s shares were down more than 22% in premarket trading. The stock closed at $25.31 on Monday.