On 10 February, Cassava Sciences, a small biotech company based in the US, announced that the US Food and Drug Administration (FDA) had denied a Citizen Petition and associated supplements filed by investors questioning the credibility of positive data from the company’s Phase IIb trial (NCT04079803) of its late-stage Alzheimer’s disease (AD) asset, simufilam. This news was a relief for Cassava and has immediately boosted the company’s shares, a much-needed upturn after extreme fluctuations over the past year. Despite this win for the company, GlobalData believes that simufilam still has further hurdles to face in securing a solid position in the AD market.
Simufilam is an orally administered filamin A inhibitor with a novel mechanism of action that restores the shape and function of altered filamin A, thereby blocking the formation of amyloid deposits and tau phosphorylation and potentially slowing AD progression. Previously reported Phase IIb data suggested that simufilam improved validated cerebrospinal fluid biomarkers of neuroinflammation and blood-brain barrier integrity, as well as cognitive scores in patients who were dosed twice daily for 28 days. In addition, Cassava is moving forward with two pivotal Phase III trials, RETHINK-ALZ (NCT04994483) and REFOCUS-ALZ (NCT05026177), which will further assess the safety and efficacy of simufilam in the treatment of mild and moderate AD. GlobalData estimates that simufilam will launch in the US in the second quarter of 2026 if positive results are achieved in Phase III trials.
In August last year, the Citizen Petition was filed by an attorney on behalf of a few investors who doubted the veracity of reported results from Cassava’s Phase IIb trial of simufilam. In particular, the company was accused of manipulating the figures of the Western blot data. Because of this, the investors asked the FDA to halt the planned Phase III trials of the drug in AD. Although the allegations of data manipulation have been disproven for the time being, concerns remain that this type of controversy will have lasting impacts on the company’s image and limit the drug’s performance in the market. This view is supported by a US key opinion leader (KOL) who was previously interviewed by GlobalData, who mentioned that they mainly knew about simufilam in the context of the data-misreporting debate.
Compounded with increased scrutiny of therapies targeting amyloid, due to the ongoing controversy surrounding Biogen and Eisai’s anti-amyloid monoclonal antibody Aduhelm (aducanumab), Cassava will need to be strategic in its marketing plans going forward. The company will also need to contend with strong competition from other late-stage pipeline candidates, including anti-amyloid beta monoclonal antibodies such as Roche’s gantenerumab and Lilly’s donanemab, in addition to other oral agents such as Alzheon’s ALZ-801 (valiltramiprosate), which also targets amyloid. As such, it may be crucial for the company to seek partnerships and licensing deals with more established companies to support its promotional and manufacturing activities before simufilam’s full market potential can be reaped.
The anticipated competition from numerous late-stage pipeline candidates, coupled with Cassava’s small size and lean commercial capabilities to penetrate the market, will likely limit the uptake of simufilam. As such, GlobalData believes that the entry of simufilam will have a modest impact on the AD market, and forecasts that the drug will reach sales of $553.7m in the US in 2030.