A Safety Study of Pimavanserin in Adult and Elderly Subjects Experiencing Neuropsychiatric Symptoms Related to Neurodegenerative Disease

Inclusion Criteria:

1. Can understand the nature of the trial and protocol requirements and provide written
informed consent. If the subject is deemed not competent to provide informed consent,
the following requirements for consent must be met:

1. The subject's legally acceptable representative (LAR) (or study
partner/caregiver, if local regulations allow) must provide written informed
consent

2. The subject must provide written (if capable) informed assent

2. Subject requires some or complete assistance with one or more of the following:

1. Instrumental activities of daily living (communication, transportation, meal
preparation, shopping, housework, managing medications, managing personal
finances) OR

2. Basic activities of daily living (personal hygiene, dressing, eating, maintaining
continence or transferring)

3. Meets clinical criteria for at least one of the following disorders, with or without
cerebrovascular disease (CVD):

1. Parkinson's disease with or without dementia as defined by the Movement Disorder
Society's Task Force

2. Dementia with Lewy bodies (DLB)

3. All-cause dementia, possible or probable Alzheimer's disease (AD)

4. Frontotemporal degeneration spectrum disorders, including possible or probable:

i. Behavioral variant frontotemporal dementia

ii. Progressive supranuclear palsy

iii. Corticobasal degeneration

e. Vascular dementia, including post-stroke dementia multi-infarct dementia and/or
subcortical ischemic vascular dementia (SIVD)

4. Has a designated study partner/caregiver

5. Can come to the clinic for study visits with a study partner/caregiver

6. If the subject is female, she must not be pregnant or breastfeeding. She must also be
of non-childbearing potential (defined as either surgically sterilized or at least 1
year postmenopausal) or must agree to use a clinically acceptable method of
contraception or be abstinent.

7. If the subject is taking an antipsychotic medication at the time of screening, the
antipsychotic medication must be discontinued 2 weeks or 5 half-lives (whichever is
longer)

Exclusion Criteria:

1. Is in hospice, is receiving end-of-life palliative care, or is bedridden

2. Has psychotic symptoms that are primarily attributable to delirium or substance abuse
(i.e., neuropsychiatric symptoms not related to neurodegenerative disease)

3. Has current evidence of an unstable neurological, cardiovascular, respiratory,
gastrointestinal, renal, hepatic, hematologic, or other medical disorder, including
cancer or malignancies that, in the judgment of the Investigator, would jeopardize the
safe participation of the subject in the study or significantly interfere with the
conduct or interpretation of the study

4. Has a known personal or family history of long QT syndrome or family history of sudden
cardiac death

5. Has a clinical significant CNS abnormality that is most likely contributing to the
dementia or findings on MRI or CT including:

1. intracranial mass lesion

2. vascular malformation

3. evidence of >4 hemosiderin deposits

6. The urine drug screen result at Visit 1 (Screening) indicates the presence of
amphetamine/methamphetamine, barbiturates, cocaine, or phencyclidine (PCP). Subjects
who test positive for amphetamines and who have a valid prescription may be retested
if they agree to abstain from the medication for the length of their participation in
the study. The presence of benzodiazepines, marijuana (THC), or opiates does not
necessarily exclude the subject from the study, as assessed by the Investigator in
consultation with the Medical Monitor.

7. Has previously been enrolled in any prior clinical study with pimavanserin or is
currently taking pimavanserinIs judged by the Investigator or the Medical Monitor to
be inappropriate for the study for any reason

Additional inclusion/exclusion criteria apply. Patients will be evaluated at screening to
ensure that all criteria for study participation are met. Patients may be excluded from the
study based on these assessments (and specifically, if it is determined that their baseline
health and psychiatric condition do not meet all pre-specified entry criteria).