FDA Approves ACADIA Pharmaceuticals’ NUPLAZID™ (pimavanserin) – The First Drug Approved for the Treatment of Hallucinations and Delusions Associated with Parkinson’s Disease Psychosis

U.S. Commercial Launch Planned for June 2016

An Estimated 40 Percent of Parkinson’s Disease Patients Have
Psychosis

Conference Call Scheduled on Monday, May 2 at 8:30 a.m. ET

SAN DIEGO–(BUSINESS WIRE)–ACADIA Pharmaceuticals Inc. (NASDAQ: ACAD), a biopharmaceutical company
focused on the development and commercialization of innovative medicines
to address unmet medical needs in central nervous system (CNS)
disorders, today announced that the U.S. Food and Drug Administration
(FDA) has approved NUPLAZID (pimavanserin) for the treatment of
hallucinations and delusions associated with Parkinson’s disease
psychosis. In 2014, the FDA designated NUPLAZID as a Breakthrough
Therapy for this condition.

“Today’s approval of NUPLAZID represents a major paradigm shift in the
treatment of Parkinson’s disease psychosis,” said Michael S. Okun, M.D.,
Medical Director of The National Parkinson Foundation. “Through its
novel and selective mechanism of action, NUPLAZID is a breakthrough
treatment that works in a whole new way – treating hallucinations and
delusions without blocking dopamine receptors and, therefore, not
impairing motor function in Parkinson’s psychosis patients.”

NUPLAZID is the first and only medicine to be approved by the FDA for
this indication. NUPLAZID is also the only drug approved by the FDA that
preferentially targets 5-HT_2A receptors. These receptors are
thought to play an important role in Parkinson’s disease psychosis. The
unique pharmacology of NUPLAZID establishes a new class of drug –
selective serotonin inverse agonists (SSIA) – by not only preferentially
targeting 5-HT_2A receptors but also avoiding activity at
dopamine and other receptors commonly targeted by antipsychotics.
Typical Parkinson’s disease therapy consists of drugs that stimulate
dopamine to treat patients’ motor symptoms such as tremor, muscle
rigidity and difficulty with walking. NUPLAZID does not interfere with
patients’ dopaminergic therapy and therefore does not impair their motor
function.

According to the National Parkinson Foundation, about one million people
in the United States and from four to six million people worldwide
suffer from Parkinson’s disease. An estimated 40 percent of these
patients have Parkinson’s disease psychosis, which is characterized by
hallucinations and delusions, is associated with significant caregiver
burden, and is a major reason for nursing home placement among
Parkinson’s patients.

“NUPLAZID represents a major medical advancement for patients with
Parkinson’s disease psychosis who suffer from hallucinations and
delusions,” said Steve Davis, ACADIA’s President and Chief Executive
Officer. “We are grateful to the many patients and investigators who
participated in NUPLAZID’s clinical studies. NUPLAZID represents the
culmination of many years of work across our entire organization to
bring this novel medicine, discovered by our scientists, to patients in
need.”

“Parkinson’s disease psychosis is a debilitating condition that adds a
tremendous burden on the lives of patients already contending with motor
issues such as slow movement, loss of balance, and muscle rigidity,”
said Todd Sherer, Ph.D., Chief Executive Officer of the Michael J. Fox
Foundation. “It also places an increased burden on caregivers and can
lead to loss of independence and nursing home admittance for patients. A
therapy to treat the hallucinations and delusions associated with
Parkinson’s disease psychosis without worsening motor symptoms can
significantly impact the lives of Parkinson’s patients and their loved
ones.”

Clinical Data

The FDA approval of NUPLAZID was based on data from the pivotal Phase
III Study -020 and other supportive studies, representing the largest
research and development program in Parkinson’s disease psychosis to
date. In Study -020, NUPLAZID significantly reduced the frequency and
severity of psychotic symptoms compared to placebo on the Scale for
Assessment of Positive Symptoms – Parkinson’s Disease (SAPS-PD). This
benefit was achieved without impairing motor function. The most common
adverse reactions (≥5% and twice the rate of placebo) in this study were
peripheral edema (7% NUPLAZID vs 3% placebo) and confusional state (6%
NUPLAZID vs 3% placebo). Results of Study -020 were published in The
Lancet. Please see full prescribing information at www.nuplazid.com.

Introducing NUPLAZIDconnect™ Patient Access and Support Services

ACADIA plans to make NUPLAZID commercially available to patients
suffering from hallucinations and delusions associated with Parkinson’s
disease psychosis in the United States in June 2016. ACADIA is committed
to ensuring that patients in the United States who are prescribed
NUPLAZID are able to access the medicine and receive the ongoing support
they may need. ACADIA will be introducing NUPLAZIDconnect, a
comprehensive program that provides financial assistance and/or access
assistance to patients, their caregivers, and physicians. NUPLAZID will
be available through a specialty pharmacy network. Patients and
physicians can access information about NUPLAZID and NUPLAZIDconnect by
visiting www.nuplazid.com
or calling 844-737-2223.

Important Safety Information and Indication for NUPLAZID (pimavanserin) tablets

WARNING: INCREASED MORTALITY IN ELDERLY PATIENTS WITH DEMENTIA-RELATED PSYCHOSIS

Elderly patients with dementia-related psychosis treated with antipsychotic drugs are at an increased risk of death. NUPLAZID is not approved for the treatment of patients with dementia-related psychosis unrelated to the hallucinations and delusions associated with Parkinson’s disease psychosis.

NUPLAZID is an atypical antipsychotic indicated for the treatment of
hallucinations and delusions associated with Parkinson’s disease
psychosis.

QT Interval Prolongation: NUPLAZID prolongs the QT interval. The use of
NUPLAZID should be avoided in patients with known QT prolongation or in
combination with other drugs known to prolong QT interval including
Class 1A antiarrhythmics or Class 3 antiarrhythmics, certain
antipsychotic medications, and certain antibiotics. NUPLAZID should also
be avoided in patients with a history of cardiac arrhythmias, as well as
other circumstances that may increase the risk of the occurrence of
torsade de pointes and/or sudden death, including symptomatic
bradycardia, hypokalemia or hypomagnesemia, and presence of congenital
prolongation of the QT interval.

Adverse Reactions: The most common adverse reactions (≥2%
for NUPLAZID and greater than placebo) were peripheral edema (7%
vs 2%), nausea (7% vs 4%), confusional state (6% vs 3%), hallucination
(5% vs 3%), constipation (4% vs 3%), and gait disturbance (2% vs <1%).

Drug Interactions: Strong CYP3A4 inhibitors (eg, ketoconazole)
increase NUPLAZID concentrations. Reduce the NUPLAZID dose by one-half.

Strong CYP3A4 inducers may reduce NUPLAZID exposure, monitor for reduced
efficacy. Increase in NUPLAZID dosage may be needed.

Renal Impairment: No dosage adjustment for NUPLAZID is needed in
patients with mild to moderate renal impairment. Use of NUPLAZID is not
recommended in patients with severe renal impairment.

Hepatic Impairment: Use of NUPLAZID is not recommended in patients with
hepatic impairment. NUPLAZID has not been evaluated in this patient
population.

Pediatric Use: Safety and efficacy have not been established in
pediatric patients.

Dosage and Administration: Recommended dose: 34 mg per day, taken
orally as two 17 mg tablets once daily, without titration.

Conference Call

ACADIA will hold a conference call and webcast on Monday, May 2, 2016 at
8:30 a.m. ET to discuss the FDA approval of NUPLAZID. The conference
call may be accessed by dialing 844-821-1109 for participants in
the U.S. or Canada and 830-865-2550 for international callers (reference
passcode 3844233). A telephone replay of the conference call may be
accessed through May 16, 2016 by dialing 855-859-2056 for callers in the
U.S. or Canada and 404-537-3406 for international callers (reference
passcode 3844233). The conference call also will be webcast live on
ACADIA’s website, www.acadia-pharm.com,
under the investors section and will be archived there until May 16,
2016.

About NUPLAZID™ (pimavanserin)

NUPLAZID is the first FDA-approved treatment for hallucinations and
delusions associated with Parkinson’s disease psychosis. NUPLAZID is a
non-dopaminergic, selective serotonin inverse agonist preferentially
targeting 5-HT_2A receptors that are thought to play an
important role in Parkinson’s disease psychosis. NUPLAZID is an oral
medicine taken once a day with a recommended dose of 34 mg (two 17 mg
tablets). ACADIA discovered this new chemical entity and holds worldwide
rights to develop and commercialize NUPLAZID.

About ACADIA Pharmaceuticals

ACADIA is a biopharmaceutical company focused on the development and
commercialization of innovative medicines to address unmet medical needs
in central nervous system disorders. ACADIA maintains a website at www.acadia-pharm.com
to which we regularly post copies of our press releases as well as
additional information and through which interested parties can
subscribe to receive e-mail alerts.

Forward-Looking Statements

Statements in this press release that are not strictly historical in
nature are forward-looking statements. These statements include but are
not limited to statements related to the benefits to be derived from
ACADIA’s product candidates, including NUPLAZID (pimavanserin); whether
NUPLAZID represents a paradigm shift in the treatment of Parkinson’s
disease psychosis (PDP) patients; whether NUPLAZID is a breakthrough
treatment that works in a whole new way; whether NUPLAZID establishes a
new class of drug; whether NUPLAZID represents a major medical
advancement for PDP patients who suffer from hallucinations and
delusions; whether a therapy to treat the hallucinations and delusions
associated with PDP without worsening motor symptoms can significantly
impact the lives of Parkinson’s patients and their loved ones; ACADIA’s
plans to make NUPLAZID commercially available in the United States,
including the timing thereof; whether ACADIA will be able to ensure
patients have access to NUPLAZID; and the assistance that will be
available to patients, their caregivers and physicians from ACADIA,
including through NUPLAZIDconnect. These statements are only predictions
based on current information and expectations and involve a number of
risks and uncertainties. Actual events or results may differ materially
from those projected in any of such statements due to various factors,
including the risks and uncertainties inherent in drug discovery,
development, and commercialization, whether NUPLAZID receives adequate
reimbursement from third-party payers, ACADIA’s ability to establish an
adequate specialty pharmacy network to distribute NUPLAZID, the degree
to which NUPLAZID receives acceptance from patients and physicians for
its approved indication, and the fact that past results of clinical
trials may not be indicative of future trial results. For a discussion
of these and other factors, please refer to ACADIA’s annual report on
Form 10-K for the year ended December 31, 2015 as well as ACADIA’s
subsequent filings with the Securities and Exchange Commission. You are
cautioned not to place undue reliance on these forward-looking
statements, which speak only as of the date hereof. This caution is made
under the safe harbor provisions of the Private Securities Litigation
Reform Act of 1995. All forward-looking statements are qualified in
their entirety by this cautionary statement and ACADIA undertakes no
obligation to revise or update this press release to reflect events or
circumstances after the date hereof, except as required by law.

Contacts

Investor Contact:
ACADIA Pharmaceuticals Inc.
Lisa
Barthelemy
(858) 558-2871
or
Media Contact:
Taft
and Partners
Ted Deutsch
(609) 578-8765
ted@taftandpartners.com