Relapse Prevention Trial Evaluating KarXT Treatment in Schizophrenia

Inclusion Criteria * Participant must have a primary diagnosis of schizophrenia for at least 1 year established by a comprehensive psychiatric evaluation based on the DSM-5-TR (American Psychiatric Association 2022) criteria and confirmed by MINI for Psychotic Disorder Studies version 7.0.2 at screening. * Participant must have experienced hospitalization for schizophrenia within 1 year from the screening date. * Participant must be experiencing residual schizophrenia symptoms and have a PANSS total score ≥70 to ≤ 110 at screening and Day -1. * Participant much have a PANSS Score of ≥ 4 (moderate or greater) on ≥ 2 of the following Positive Scale (P) items at screening and Day -1: 1. Item 1 (P1; delusions) 2. Item 2 (P2; conceptual disorganization) 3. Item 3 (P3; hallucinatory behavior) 4. Item 6 (P6; suspiciousness/persecution) * Participant must have a CGI-S score of ≥ 4 at screening and Day -1 * Participant must have a BMI ≥ 18 and ≤ 40 kg/m2. Exclusion Criteria * Participant must not have any primary DSM-5 disorder other than schizophrenia within 12 months before screening * Participants must not have a newly diagnosed or are experiencing their first treated episode of psychosis or schizophrenia. * Participant must not have a risk of suicidal behavior as determined by the Investigator's clinical assessment and/or Columbia-suicide Severity Rating Scale (C-SSRS). * Participant must not have had psychiatric hospitalization(s) for more than 30 days (cumulative) within the 6 months before screening. * Participant must not have a history of treatment resistance to schizophrenia medications * Participant must not have decrease in PANSS total score (floor adjusted) between screening and Day -1 of more than 20%. * Other protocol-defined Inclusion/Exclusion criteria apply.