Corporate Presentation

Creating the Next Generation of CNS Drugs

January 12, 2015

Forward-Looking Statement

This presentation contains forward-looking statements. These statements relate to future events and involve known and unknown risks, uncertainties and other factors which may cause our actual results, performance or achievements to be materially different from any future results, performances or achievements expressed or implied by the forward-looking statements. Each of these statements is based only on current information, assumptions and expectations that are inherently subject to change and involve a number of risks and uncertainties. Forward-looking statements include, but are not limited to statements about (i) the plans for, including timing and progress of, clinical development, clinical trials and commercialization for our product candidates, including NUPLAZID™ (pimavanserin); (ii) the timing of any submission or application for, or receipt of, regulatory clearances and approvals, any potential approval of NUPLAZID as a first-in-class drug for PDP or potential approval for other indications; (iii) the benefits to be derived from and efficacy of our product candidates, including the clinical benefits of NUPLAZID, in PDP, ADP, schizophrenia or other neurological or psychiatric indications, the potential advantages of NUPLAZID versus existing antipsychotics, the potential for NUPLAZID to represent a new class of psychosis medicine, and the expansion opportunities for NUPLAZID; (iv) estimates regarding the prevalence of PD, PDP, ADP or schizophrenia; (v) the potential market for any of our product candidates, including NUPLAZID; and (vi) our estimates regarding our cash position or capital requirements.

In some cases, you can identify forward-looking statements by terms such as “may,” “will,” “should,” “could,” “would,” “expects,” “plans,” “anticipates,” “believes,” “estimates,” “projects,” “predicts,” “potential” and similar expressions (including the negative thereof) intended to identify forward looking statements. Given the risks and uncertainties, you should not place undue reliance on forward-looking statements. For a discussion of the risks and other factors that may cause our actual results, performance or achievements to differ, please refer to our annual report on Form 10-K for the year ended December 31, 2013, as well as our subsequent filings with the SEC. The forward-looking statements contained herein are made as of the date hereof, and we undertake no obligation to update them for future events.

2

ACADIA: A CNS Focused Biopharmaceutical Company

• Building a leading U.S. specialty CNS franchise

• NUPLAZID™ (pimavanserin), a differentiated and potential new class of

psychosis therapy

– Potential to be first and only drug approved in U.S. for Parkinson’s disease

psychosis (PDP)

– Demonstrated strong efficacy and favorable safety profile in Phase III PDP trial

• Broad opportunity for pimavanserin to expand into range of neurological

and psychiatric indications

– Potential to transform treatment paradigm in large underserved indications

• Worldwide commercialization rights to NUPLAZID

3

NUPLAZID (Pimavanserin) Potential New Class of Psychosis Therapy

• Selective serotonin inverse agonist preferentially targeting 5-HT2A receptors

• Small molecule NCE discovered and developed by ACADIA

• FDA granted Breakthrough Therapy designation in 2014

• Completed Phase III PDP Program:

- NDA submission planned for Q1 15

- MAA submission planned six to nine months after NDA submission

• Conducting Phase II study in Alzheimer’s disease psychosis (ADP)

• Major life cycle expansion opportunities in neurological and psychiatric indications

• U.S. patents go into 2028

4

Parkinson’s Disease Psychosis An Unmet Medical Need

• Characterized by hallucinations and

delusions

• Chronic disorder; worsens over time

and severely impacts daily living

• Afflicts about 40% of the 1 million

Parkinson’s patients in the U.S.

• Leading cause of nursing home

placement of Parkinson’s patients

• No drug approved by FDA for PDP

5

Current Antipsychotics Not Approved for PDP and Increase Mortality and Morbidity

• Can counteract PD dopamine replacement therapy resulting in a worsening of motoric symptoms

• Significant side effects are problematic for frail elderly population; sedation, stroke, hematological disorder, cardiovascular events, and cognitive impairment

• Not approved by the FDA for PDP

• Black box 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.”

6

NUPLAZID: Differentiation From Atypical Antipsychotics

7

NUPLAZID’s selective, non-dopaminergic profile enables treatment of PDP without compromising motor control

5-HT2A D2 H1

NUPLAZID™ ― ― ―

Seroquel

Zyprexa

Risperidone ―

Clozapine

NUPLAZID: Key Findings From Phase III -020 Study

8

• 6-week double blind placebo-controlled study in 199 PDP patients randomized to 40 mg of NUPLAZID or placebo (1:1)

• Highly significant and clinically meaningful improvement in psychosis

• Significant improvement on all additional efficacy measures: nighttime sleep, daytime wakefulness and caregiver burden

• Favorable safety and tolerability profile - no worsening of motor function

Source: Cummings et al., Lancet (2014) 383

-8

-6

-4

-2

0

1 15 29 43

SAP

S-P

D Im

pro

vem

en

t (

LSM

± S

E)

Study Day Placebo 40 mg NUPLAZID

p = 0.001

p = 0.037

-020 Study: NUPLAZID Demonstrated Highly Significant Reduction in Psychosis

9

-2.73

-5.79

-7

-6

-5

-4

-3

-2

-1

0

Placebo 40 mg PIM

SAP

S-P

D I

mp

rove

me

nt

Change from Baseline to Day 43 (LSM + SE)

SAPS-PD (primary endpoint) (ITT, N=185; change from baseline)

-020 Study: NUPLAZID Showed Highly Significant Efficacy as Assessed by Different Raters and Scales

Endpoint Rater p-value*

SAPS-PD Centralized Independent

0.001

SAPS H+D Centralized Independent

0.001

CGI-I Investigator 0.001

CGI-S Investigator <0.001

*ITT, MMRM, OC

10

-020 Study: NUPLAZID Improved Nighttime Sleep and Daytime Wakefulness

11

-3

-2.5

-2

-1.5

-1

-0.5

0

0.5

1 15 29 43

Study Day

Placebo 40 mg NUPLAZID

p = 0.045 p = 0.001

-3

-2.5

-2

-1.5

-1

-0.5

0

0.5

1 15 29 43

Study Day

Placebo 40 mg NUPLAZID

p = 0.012

Daytime Wakefulness (ITT, N=185; change from baseline)

Nighttime Sleep (ITT, N=185; change from baseline)

SCO

PA Im

pro

vem

en

t (L

SM

SE)

SCO

PA Im

pro

vem

en

t (L

SM

SE)

-020 Study: NUPLAZID Reduced Caregiver Burden

12

-6

-5

-4

-3

-2

-1

0

1

2

1 15 29 43

Car

egi

ver

Bu

rde

n Im

pro

vem

en

t (L

SM

SE)

Study Day Placebo 40 mg NUPLAZID

p = 0.002

Caregiver Burden (ITT, N=185; change from baseline)

NUPLAZID PDP Program Open-Label Safety Extension Studies

• ~800 patient years of exposure in PDP

– > 250 patients treated ≥ 1 year

– > 100 patients treated ≥ 2 years

– Longest patient exposure > 9 years

• Favorable long-term safety and tolerability profile observed to date in fragile, elderly patients

• Differentiation from off-label use of antipsychotics

13

Parkinson’s Disease Psychosis Patient Profile

14

• Average age around 74 years

• Around 60/40 split between men and

women

• Over 70% suffer comorbid sleep

disturbances

• Almost 90% have caregiver support

with 74% requiring daily care

Source: Based on ACADIA market research with over 800 PDP-treating physicians and over 700 PDP patient chart audits

Parkinson’s Disease Psychosis ACADIA Market Research

• Treating physicians surveyed were dissatisfied with use of atypical antipsychotics for PDP patients:

– Safety and tolerability issues

– Black-box warning

– Impact on motor function

• Physicians’ top-ranked attributes for PDP product:

– “Does not negatively impact motor symptoms”

– “Resolves psychosis fully”

– “Low incidence of side effects”

• These top-ranked attributes compare favorably with the profile we have observed with NUPLAZID in the clinic

Source: Based on ACADIA market research with over 800 PDP-treating physicians and over 700 PDP patient chart audits.

15

PDP: U.S. Payer Landscape

• ACADIA has conducted foundational access and reimbursement research with key decision makers for payers covering 168 million lives:

• Payers responded favorably to NUPLAZID’s target product profile. Most valued attributes:

– Reduction in psychotic symptoms

– Safety and tolerability profile

– No worsening of motor function

– Delaying institutionalization

16

Payer Landscape

Medicare Part D

Standard

Medicaid Medicare Part D LIS

Commercial

PDP-Treating Physicians Landscape

17

• 11,000 PDP-Treating

Physicians:

- Neurologists comprise the largest group

- Psychiatrists

- Long-term care physicians

• 135 Sales Reps will be

hired at approval

Commercial Preparations for Planned Launch of NUPLAZID Executing on Plan

• Building out ACADIA commercial organization:

– Preparing commercial infrastructure and systems, including supply chain distribution

– Planning to hire 135 sales representatives at approval

• Completed extensive market research to understand:

– PDP market landscape

– Physicians’ current treatment behaviors, view of unmet medical need and prescribing patterns

– PDP patients’ and caregivers’ needs

• Conducted national and regional scientific advisory boards

• Launching PDP disease awareness campaign

18

Pimavanserin Life Cycle Management PDP Provides Strategic Entry into Other Indications

19

Psychiatric Neurological

Psychosis Parkinson’s Alzheimer’s Lewy Body Dementia

Schizophrenia Depression

Mania

Pimavanserin has the potential to be a transformative advancement in the treatment of psychosis

Alzheimer’s Disease Psychosis (ADP) Neurology Expansion Opportunity For Pimavanserin

20

• ADP afflicts 25% to 50% of the 5.2 million Alzheimer’s disease patients in U.S.

• No drug approved by FDA for ADP

• Current antipsychotics have black box warning for use in elderly demented patients

• MOA and safety profile of pimavanserin potentially attractive for ADP

• Development and regulatory synergies with PDP

• Phase II ADP trial initiated in late 2013

Phase II ADP Trial (-019 Study): Design

Patient Pathway From Screening to Treatment Period

21

Phase II Efficacy, Tolerability and Safety Study

Location Nursing homes at Biomedical Research Centre for Mental Health, Kings College

Patients Target enrollment of 200 ADP patients

Type of design Randomized, double-blind, placebo-controlled

Key efficacy endpoints NPI-NH, CMAI-SF, ADCS-CGIC

12-Week Blinded Treatment Period

Baseline 4-Week Visit

6-Week Key Endpoint

12-Week Cognitive Endpoint

Screening

NPI-NH 2-Week Visit

BPST Run-In 40 mg PIM or PBO (1:1)

9-Week Visit

22

Schizophrenia Psychiatric Expansion Opportunity for Pimavanserin

• A debilitating lifelong disease afflicting 1% of population

• Current therapies are sub-optimal

• Pimavanserin profile may allow for an improved schizophrenia therapy

— Phase II PoC demonstrated advantages of co-therapy

— Potential use as stand-alone maintenance therapy to improve compliance

0.0

5.0

10.0

15.0

20.0

25.0

30.0

PAN

SS Im

pro

vem

en

t Pimavanserin Co-Therapy Phase II Schizophrenia Trial

Pimavanserin co-therapy (PIM/RIS) demonstrated equivalent efficacy with less weight gain

0.0

0.5

1.0

1.5

2.0

2.5

3.0

We

igh

t C

han

ge (

kg)

Change in Mean PANSS Score from Baseline

Mean Change in Weight from Baseline

p = 0.05 p = 0.007

RIS LD PIM/RIS RIS HD RIS LD PIM/RIS RIS HD

23

Meltzer et al., Schizophrenia Research (2012)

Pipeline

COMPOUND/ PROGRAM

INDICATION DISCOVERY IND-TRACK PHASE I PHASE II PHASE III REGULATORY

APPROVAL

COMMERCIALIZATION

RIGHTS

NUPLAZID™

(pimavanserin)

Parkinson’s

Disease Psychosis

Alzheimer’s Disease

Psychosis

Schizophrenia

ACADIA

Adrenergic Chronic Pain Allergan

Muscarinic Glaucoma Allergan

ER Neuroprotection

and Chronic Pain ACADIA

Nurr-1 Parkinson’s Disease ACADIA

24

Corporate Information

Profile:

• Based in San Diego

• 95 employees

Financial:

• Cash position at

September 30, 2014(1): $338M

(1) Reflects cash, cash equivalents and investment securities

25

ACADIA Key Priorities

• NUPLAZID - Parkinson’s disease psychosis

– Submit NDA to FDA in Q1 15

– Submit MAA to EMA around six to nine months following NDA submission

– Execute on commercial preparations for successful launch of NUPLAZID in U.S.

• Pimavanserin - Alzheimer’s disease psychosis

– Complete enrollment in Phase II study by end of 2015

• Pimavanserin life cycle management

– Initiate Phase II study with pimavanserin in PD patients with sleep disturbances in H1 15

– Initiate Phase II study with pimavanserin in patients with schizophrenia in H2 15

26

ACADIA: A CNS Focused Biopharmaceutical Company

• Building a leading U.S. specialty CNS franchise

• NUPLAZID™ (pimavanserin), a differentiated and potential new class of

psychosis therapy

– Potential to be first and only drug approved in U.S. for Parkinson’s disease

psychosis (PDP)

– Demonstrated strong efficacy and favorable safety profile in Phase III PDP trial

• Broad opportunity for pimavanserin to expand into range of neurological

and psychiatric indications

– Potential to transform treatment paradigm in large underserved indications

• Worldwide commercialization rights to NUPLAZID

27

Creating the Next Generation of CNS Drugs