Acadia Pharmaceuticals Receives FDA Fast Track Designation for Remlifanserin in Alzheimer's Disease Psychosis

SAN DIEGO—(BUSINESS WIRE)—Acadia Pharmaceuticals Inc. (Nasdaq: ACAD) today announced that the U.S. Food and Drug Administration (FDA) has granted Fast Track designation to remlifanserin, an investigational, highly selective, 5-HT2A receptor inverse agonist, for the treatment of hallucinations and delusions associated with Alzheimer’s disease psychosis (ADP).

Fast Track designation is designed to facilitate the development and expedite the review of drugs intended to treat serious conditions and fill an unmet medical need, with the goal of getting important new drugs to patients earlier.

“FDA Fast Track designation for remlifanserin underscores the significant unmet need for new treatment options for people living with Alzheimer’s disease psychosis, a serious condition for which there are currently no FDA-approved therapies,” said Catherine Owen Adams, Chief Executive Officer of Acadia. “This is an important milestone for the remlifanserin program, and we look forward to sharing upcoming topline data from the RADIANT Phase 2 trial as we continue to advance remlifanserin as a potential new treatment option for patients and families impacted by this devastating condition.”

Acadia is also providing an update on RADIANT, its development program evaluating remlifanserin for the treatment of hallucinations and delusions associated with ADP. Enrollment in the Phase 2 portion of the program has been completed, and the Company now expects to report topline results in September to October 2026. Consistent with RADIANT’s operationally seamless design, screening and enrollment are underway in the Phase 3 studies.

About Remlifanserin

Remlifanserin (ACP-204) is a potent and highly selective serotonin 5-HT2A receptor inverse agonist for the treatment of Alzheimer’s disease and Lewy body–associated psychosis and is believed to reduce hallucinations and delusions through selective 5-HT2A receptor inverse agonism, potentially restoring excitatory/inhibitory (E/I) balance without direct dopamine (D2) blockade and avoiding the common safety and tolerability issues associated with atypical antipsychotics.^1,2

About Acadia Pharmaceuticals

Acadia is committed to turning scientific promise into meaningful innovation that makes the difference for underserved neurological and rare disease communities around the world. Our commercial portfolio includes the first and only FDA-approved treatments for Parkinson’s disease psychosis and Rett syndrome. We are developing the next wave of therapeutic advancements with a robust and diverse pipeline that includes mid- to late-stage programs in Alzheimer’s disease psychosis and Lewy body dementia psychosis, along with earlier-stage programs that address other underserved patient needs. At Acadia, we’re here to be their difference. For more information, visit us at acadia.com and follow us on LinkedIn and X.

Forward-Looking Statements

This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Forward-looking statements include all statements other than statements of historical fact and can be identified by terms such as “may,” “will,” “should,” “could,” “would,” “intends,” “expects,” “plans,” “anticipates,” “believes,” “estimates,” “projects,” “predicts,” “potential,” “guidance,” “continue” and similar expressions (including the negative thereof) intended to identify forward-looking statements. Forward-looking statements contained in this press release include, but are not limited to, statements about the potential efficacy and safety of remlifanserin as a treatment for Alzheimer’s disease psychosis, the FDA’s potential review of a new drug application for remlifanserin as a treatment for Alzheimer’s disease psychosis, the receipt and timing of the topline results of the RADIANT Phase 2 study, and the enrollment of the Phase 3 portion of the RADIANT development program. Forward-looking statements are subject to known and unknown risks, uncertainties, assumptions and other factors that may cause our actual results, performance or achievements to differ materially and adversely from those anticipated or implied by our forward-looking statements. Such risks, uncertainties and other factors include, but are not limited to, the inherent uncertainty regarding development of product candidates; our ability to obtain necessary regulatory approvals to commercialize our products and product candidates; if and when approved, market acceptance of our products and our ability to continue to stay in compliance with applicable laws and regulations. Given the risks and uncertainties, you should not place undue reliance on these forward-looking statements. For a discussion of these and other risks, uncertainties and other factors that may cause our actual results, performance or achievements to differ, please refer to our quarterly report on Form 10-Q for the period ended March 31, 2026, filed on May 7, 2026, as well as our subsequent filings with the Securities and Exchange Commission from time to time. The forward-looking statements contained herein are made as of the date hereof, and we undertake no obligation to update them after this date, except as required by law.

References

¹ Burstein ES. Relevance of 5-HT2A receptor modulation of pyramidal cell excitability for dementia-related psychosis: implications for pharmacotherapy. CNS Drugs. 2021;35(7):727-741. doi:10.1007/s40263-021-00836-7

² Burstein ES, Dey PM, Pathak S. Nonclinical characterization of ACP-204, a novel second-generation 5-HT2A inverse agonist. Poster presented at: Alzheimer’s Association International Conference (AAIC); July 27-31, 2025; Toronto, Canada.