On December 15, 2025, Cassava Sciences Received A Formal Letter From FDA Confirming That The Proposed Clinical Trial Is On Full Clinical Hold Subject To The Company Providing FDA With Additional Information

Following previously reported communications with the U.S. Food and Drug Administration ("FDA") regarding Cassava Sciences, Inc.'s ("Cassava" or the "Company") investigational new drug application (IND) and proposed proof-of-concept clinical trial for simufilam in tuberous sclerosis complex ("TSC")-related epilepsy, on December 15, 2025, the Company received a formal letter from FDA confirming that the proposed clinical trial is on full clinical hold subject to the Company providing FDA with additional information, including additional pre-clinical data, and modifying the protocol design.

Cassava intends to work expeditiously to address the items identified in the letter, however, the Company no longer expects to initiate a proof-of-concept clinical trial for simufilam in TSC-related epilepsy in the first half of 2026 as previously disclosed. The updated timing for initiation of a clinical trial will depend on the Company's ability to provide the requested information and on satisfactory completion of FDA's review.