Acadia Pharmaceuticals has resubmitted the supplemental New Drug Application (sNDA) for pimavanserin for the treatment of hallucinations and delusions associated with Alzheimer disease psychosis to the Food and Drug Administration (FDA).

Acadia originally submitted the sNDA in July 2020. The application included data from the phase 3 HARMONY ( Identifier: NCT03325556) and phase 2 Study-019 ( Identifier: NCT02035553) trials. 

The FDA subsequently issued a Complete Response Letter (CRL) in April 2021 citing “a lack of statistical significance in some of the subgroups of dementia, and insufficient numbers of patients with certain less common dementia subtypes as lack of substantial evidence of effectiveness to support approval.” 

Additionally, the FDA noted that the phase 2 Alzheimer disease psychosis study (Study-019), was not adequate and well controlled. According to the Agency, the single center study did not have “type I error control of secondary endpoints in which certain protocol deviations occurred.”

To address the issues raised in the CRL, the Company provided additional analyses from the HARMONY and Study-019 trials in the resubmitted application to support the use of pimavanserin for Alzheimer disease psychosis.

Pimavanserin is currently marketed under the brand name Nuplazid® and is approved for the treatment of hallucinations and delusions associated with Parkinson disease psychosis. There is currently no FDA-approved treatment for Alzheimer disease psychosis.


Acadia Pharmaceuticals announces resubmission of supplemental New Drug Application to US FDA for Nuplazid® (pimavanserin) to treat Alzheimer’s disease psychosis. News release. Acadia Pharmaceuticals Inc. Accessed February 16, 2022.