A Phase 3, Randomized, Double-Blind, Placebo-Controlled Study to Evaluate the Efficacy and Safety of Adjunctive Pimavanserin for the Treatment of Schizophrenia (Enhance-2)

INTERVENTION: Product Name: Pimavanserin Product Code: ACP‐103 Pharmaceutical Form: Tablet INN or Proposed INN: Pimavanserin CAS Number: 706782‐28‐7 Current Sponsor code: ACP‐103 Other descriptive name: PIMAVANSERIN TARTRATE Concentration unit: mg milligram(s) Concentration type: equal Concentration number: 10‐ Pharmaceutical form of the placebo: Tablet Route of administration of the placebo: Oral use Product Name: Pimavanserin Product Code: ACP‐103 Pharmaceutical Form: Tablet INN or Proposed INN: Pimavanserin CAS Number: 706782‐28‐7 Current Sponsor code: ACP‐103 Other descriptive name: PIMAVANSERIN TARTRATE Concentration unit: mg milligram(s) Concentration type: equal Concentration number: 10‐ Pharmaceutical form of the placebo: Tablet Route of administration of the placebo: Oral use Product Name: Pimavanserin Product Code: ACP‐103 Pharmaceutical Form: Tablet INN or Proposed INN: Pimavanserin CAS Number: 706782‐28‐7 Current Sponsor code: ACP‐103 Other descriptive name: PIMAVANSERIN TARTRATE Concentration unit: mg milligram(s) Concentration type: equal Concentration number: 17‐ Pharmaceutical form of the placebo: Tablet Route of administration of the placebo: Oral use CONDITION: Schizophrenia ; MedDRA version: 20.0 Level: PT Classification code 10039626 Term: Schizophrenia System Organ Class: 10037175 ‐ Psychiatric disorders Therapeutic area: Psychiatry and Psychology [F] ‐ Mental Disorders [F03] PRIMARY OUTCOME: Main Objective: The primary objective of the study is to evaluate the efficacy of adjunctive pimavanserin compared with adjunctive placebo in the treatment of schizophrenia Primary end point(s): Change from Baseline to Week 6 in the Positive and Negative Syndrome Scale (PANSS) total score Secondary Objective: To evaluate the safety and tolerability of adjunctive pimavanserin compared to adjunctive placebo in the treatment of schizophrenia Timepoint(s) of evaluation of this end point: from Baseline to Week 6 SECONDARY OUTCOME: Secondary end point(s): Key Secondary Endpoint: ; Change from Baseline to Week 6 in the Clinical Global Impression – Severity scale (CGI‐S) score ; ; Other Secondary Endpoints: ; Change from Baseline to Week 6 in PANSS subscores ; • Clinical Global Impression – Improvement (CGI‐I) score at Week 6 ; • Proportion of responders at Week 6 according to each of the following: ; – PANSS (=20% and =30% reduction in PANSS total score) ; – CGI‐I (CGI‐I score of 1 or 2) ; • Change from Baseline to Week 6 in Personal and Social Performance (PSP) scale score ; • Change from Baseline to Week 6 in 10‐item Drug Attitude Inventory (DAI‐10) score ; • Change from Baseline to Week 6 in Karolinska Sleepiness Scale (KSS) score Timepoint(s) of evaluation of this end point: from Baseline to Week 6 INCLUSION CRITERIA: 1. Male or female, =18 and =55 years of age at time of Screening 2. Able to understand and provide signed informed consent 3. Able to sign and date a request for medical records and/or subject privacy form if applicable according to local regulations 4. In the Investigator’s opinion, is able to understand the nature of the trial, follow protocol requirements, be willing to comply with study drug administration, and discontinue prohibited concomitant medications 6. Able to complete subject‐reported outcome measures, can be reliably rated on assessment scales, and is willing to particip 5. Has a caregiver or some other identified responsible person (e.g., family member, social worker, caseworker, or nurse) considered reliable by the Investigator in providing support to the subject to help ensure compliance with study treatment, study visits, and protocol procedures and who is also able to provide input helpful for completing study rating scales