Lab named by Cassava to back up Alzheimer's data says it wasn't involved, sending biotech's shares into freefall again

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The citizen petition dealt a blow to Cassava’s shares earlier this week, driving the value down 30% to $82. (Pixabay)

Cassava Sciences’ battle over the science backing up an Alzheimer’s disease treatment took another turn Friday, as one of the companies involved in laboratory work for the therapy denied involvement in preparing some of the data in question.

Shares of Cassava crashed once again, opening down more than 20% to $54 as the markets opened Friday. This compares to a prior close of $80.  

Quanterix, a digital health company focused on digitizing biomarker analysis, was cited by Cassava in a Wednesday rebuttal to a citizens petition defending the science behind the Alzheimer’s therapy simufilam. The whistleblower complaint filed with the FDA claims that Cassava’s scientific evidence contains data anomalies and manipulation, including image alteration.

Cassava is taking a different approach than other Alzheimer’s therapies by trying to stabilize a scaffolding protein called filamin A rather than clear amyloid plaques from the brain. The petition claims that no other lab has confirmed the connection between filamin A and the devastating neurological disorder.

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In a response, Cassava claimed that Quanterix generated some of the data from Alzheimer’s patients that was presented at the Alzheimer’s Association International Conference in July 2021. The presentation concluded that treatment with simufilam improved cognition and neuropsychiatric conditions in patients with Alzheimer’s disease.

But Quanterix says it had nothing to do with the data in that presentation. While Cassava previously used the research technology company’s laboratory to perform sample testing, the data charts that were presented at the conference were not interpreted or prepared by Quanterix or its employees.

CEO Remi Barbier explained the situation with Quanterix in an emailed statement, noting an "absence of any disagreements between Quanterix and Cassava Sciences on this matter."

"We both had a job to do, we both did our respective jobs and we co-authored the results in an abstract at a major scientific conference," Barbier said. 

A more detailed statement posted late Friday morning said that Quanterix was contracted to perform sample testing on blinded samples for the phase 2b study conducted by Cassava. The lab was tasked with measuring levels of p-tau in plasma from the study's subjects. P-tau is considered a diagnostic biomarker for Alzheimer's. 

“To ensure data integrity, it is standard industry practice to keep separate the people who generate the data from the people who analyze the data,” said Barbier in the statement. “That certainly was the case here. Anything different is a distortion of the facts.”

Cassava said that the sample testing was conducted by Quanterix employees and then handed to the biotech in raw form for analysis of any potential treatment effect for simufilam. The results were displayed in the resulting poster presentation at the conference. 

The citizen petition dealt a blow to Cassava’s shares earlier this week, driving the value down 30% to $82. Barbier told Fierce Biotech at the time that the company stands by its science and dismissed the complaint as “Wall Street shenanigans.” 

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Barbier said the company is unaware of who is behind the petition, which was launched by law firm Labaton Sucharow. The firm responded to Cassava's Wednesday rebuttal, noting discussion in the scientific community about some of the issues raised by the petition.

One of the issues that several scientists have discussed since the petition dropped is the use of Western blot images, a commonly used technique in biotechnology to identify certain proteins within a complex mixture of proteins that have been extracted from cells. The petition alleges that some of these images were manipulated. 

The statement also noted that the petition was launched by clients with expertise in neuroscience, drug discovery, biochemistry and finance. The clients also hold short positions in Cassava's stock. 

Editor's Note: This story was updated at 11:57 a.m. ET on Aug. 27, 2021 to include comments from Cassava CEO Remi Barbier.