Protocol Ver1.00 (28 June 2019) was amended: Added Phase of development to synopsis. Minor wording clarifications C-SSRS endpoint. Inclusion 5 was amended and 6,18 were added. Clarified that DSM-5 criteria must be met at screening. Added Sec10.7 for eligibility adjudication process to Sec10. Exclusion 2 subject’s substance use disorder criteria were further restricted. Exclusion 10 part a & part g were updated to exclude subjects with unstable hypertension. Subjects with an ECG that has a centrally overall interpretation of abnormal, significant/potentially clinically significant must be discussed with Medical Monitor(MM). Exclusion 14 was added to require that specific blood pressure thresholds be met. Exclusion 15 was clarified: to indicate who determines clinical significance of abnormal lab values at Screening and to require that the MM approve retesting of clin lab tests and allow extensions to the screening period for technical issues. Exclusion 16 was clarified to always exclude subjects with a positive/indeterminate confirmatory test for hepatitis C. Simplified language for exclusion 21 for positive drug test at screening. Exception for subjects testing positive for cannabinoids at Screening was removed. Exclusion 22 made prior receipt of investigational drug product or device more restrictive. Clarified Other Safety Endpoint that suicidal ideation endpoint includes frequency and severity. Clarified the timing for obtaining consents. Added footnote to indicate a separate consent form is required for the duplicate subject check at screening. Clarified that pretreatment events and adverse events are determined programmatically. Clarified that the PANSS-IC form will be completed as part of PANSS. Sec 10.3 added clarification on collection of data. Clarification was made to allow antipsychotic medications to be reported in eCRF based on subject and caregiver input. Expectations on details of prior psychotropic medications were clarified.

The protocol Version 2.00 dated 16 September 2020 is being amended as follows: Updated Exclusion Criteria #2 based on FDA feedback to make the criterion more specific while still maintaining the original intent of the criterion, which is to exclude subjects with a history of substantial substance use disorder that may result in significant confounding on diagnosis, presentation and/or treatment responsiveness. Updated Exclusion Criteria #22 based on FDA feedback to refine the restrictions on prior clinical trial participation to those that would meaningfully interfere with the conduct of the study. Updated frequency of Data Safety Monitoring Board (DSMB) to align with the DSMB charter. Update Sunovion Responsible Physician. Minor changes such as edits to the title page, headers, footers, and approval page of the document to reflect the new version number and document date have also been made. Updates to abbreviations for consistency, added phase of development, minor wording clarifications for readability, corrections to cross-references, and corrections to typographical errors have been made. Updates to the table of contents have also been made. These changes are not described within.