Acadia Pharmaceuticals ($ACAD) Pimavanserin Approval Case

The court has ruled on whether the plaintiffs are certified as a class.

S.D. California

Court

3:21-CV-00762

Case number

09/09/2019

Class period Start

04/04/2021

Class period End

$ACAD investors filed a claim against Acadia Pharmaceuticals for allegedly promoting a flawed study and overstating FDA support for its plan to expand pimavanserin for dementia-related psychosis.
After Acadia disclosed that the FDA had identified deficiencies in its application to expand pimavanserin, $ACAD fell 45.35% on March 9, 2021.
$ACAD investors can join this case to be notified about potential recovery.
Case Details:

Between September 9, 2019 and April 4, 2021, Acadia Pharmaceuticals told investors its Phase III HARMONY study produced strong results and could support broad approval of pimavanserin for dementia-related psychosis. Executives emphasized that the FDA had agreed the company could rely on a single well-controlled study, along with supportive data from earlier studies, to seek that broader label.

However, during this period, investors allege the HARMONY study was not built to show the drug worked across the different dementia subtypes Acadia Pharmaceuticals wanted to treat, and the supporting data was weaker than the company suggested. 

Acadia Pharmaceuticals allegedly failed to disclose that key subgroup sample sizes were too small, especially for less common dementia types, making the study underpowered. The results outside Parkinson ’s-related patients were disappointing, and in some groups did not show meaningful benefit. 

The FDA had not actually agreed to the broad approval path Acadia described, while the supportive Alzheimer’s study also had design and protocol problems.

Then, on March 8, 2021, the company revealed that the FDA had identified deficiencies in its review of the pimavanserin application that blocked discussions about labeling and postmarketing requirements. $ACAD fell 45.35%, closing at $25.02. 

Additional revelations followed on April 5, 2021, including a Complete Response Letter stating that some dementia subgroups lacked statistical significance, some less common subtypes had too few patients, and the supportive Alzheimer’s study was not adequate and well-controlled. 

Based on these events, $ACAD investors filed a claim against Acadia Pharmaceuticals, alleging the company:
It overstated the strength of the HARMONY study.
It hid that several dementia subgroups were too small and that the non-Parkinson’s data did not provide strong evidence that pimavanserin worked across the broad population it targeted.
It told investors the FDA supported its approval strategy, which investors allege kept $ACAD inflated until the FDA’s review exposed the weaknesses in the submission.
Investors argue Acadia Pharmaceuticals misled the market about the strength of its clinical evidence and its path to broader FDA approval, causing losses when the truth emerged.

Case Type

US Securities Class Action

Case Status

Class Certification result

Alleged Offence

Misleading Statements,

Fraud,

Failure to Disclose,

Omissions

Suspected Party

Directors,

Management

Security Type

Stocks

Trade Direction

Long

Shock Event Date

03/08/2021

Filing date

12/10/2021

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