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Cassava (SAVA) Down as Quanterix Issues Statement on AD Study

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Shares of Cassava Sciences, Inc. (SAVA - Free Report) plunged 17.7% again on Aug 27 after tumbling last week on questions about its integrity on studies being conducted on its Alzheimer’s disease (AD) candidate.

Quanterix Corporation (QTRX - Free Report) , a company digitizing biomarker analysis, stated that neither it nor its employees interpreted the test results or prepared the data charts presented by Cassava at the Alzheimer’s Association International Conference in July 2021 or otherwise. Cassava’s shares tumbled following the statement.

The company is developing simufilam for the treatment of AD. The test results in question are plasma p-tau analysis from a previously disclosed randomized, controlled phase IIb study in patients with AD.

The phase IIb study was conducted by Cassava. In response, Cassava stated that Quanterix’s sole responsibility with regard to this clinical study was to perform sample testing, specifically to measure levels of p-tau in plasma samples collected from study subjects. Per the company, it is the norm of the industry to separate the people who generate the data from the people who analyze the data.

It further added that Quanterix’s employees did not know whether the samples were from placebo, or from simufilam-treated patients. It conducted sample testing and then sent raw data to Cassava for analysis of treatment effects.

Cassava’s stock has surged 673.3% in the year so far against the industry’s decrease of 11.6%.


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Shares plunged significantly on Aug 25 following news of the petition requesting the FDA to halt the current clinical studies of simufilam questioning integrity of the studies on various grounds.

Per the petition, biomarker data is generated by Cassava or its science collaborators and therefore are falsified. Among others, it was also alleged that extensive use of Western blot analysis is foundational to Cassava’s research, and western blots data appear overexposed and highly processed, suggesting image manipulation.

Cassava had then clarified that plasma p-tau data from Alzheimer’s patients were generated by Quanterix.  Per the company, it has reached an agreement with the FDA on Special Protocol Assessments (SPA) for its phase III studies of simufilam for the treatment of AD. The SPAs underscore alignment with the FDA on key scientific, clinical and regulatory requirements of the phase III program of simufilam in AD. 

Quite a few companies are striving hard to get their AD drugs approved. The FDA approval of Biogen’s (BIIB - Free Report) AD drug, Aduhelm, has put the spotlight on this promising yet challenging space. In June 2021, Biogen and partner Eisai won the FDA approval for Aduhelm (aducanumab-avwa) as the first and only AD treatment, after a few setbacks.

Among the companies developing drugs for the same is Eli Lilly (LLY - Free Report) .  The company is developing donanemab, an investigational antibody therapy for AD. In June, the FDA granted Breakthrough Therapy designation to donanemab for AD.  Prothena’s PRX005 is also being evaluated for the treatment of AD.

Cassava currently has a Zacks Rank #3 (Hold). You can see the complete list of today’s Zacks #1 Rank (Strong Buy) stocks here.