A Study to Evaluate the Efficacy and Safety of KarXT for the Treatment of Manic Episodes in Bipolar-I Disorder

Inclusion Criteria

• Participants must have a primary diagnosis of Bipolar-I disorder established by acomprehensive psychiatric evaluation.

• Participants must be experiencing an acute episode or relapse of mania or mania withmixed features (≤ 3 weeks).

• Participants must require hospitalization for the acute exacerbation or relapse ofmania.

• Participants must have all psychotropic medications washed out in no more than 14days prior to the first dose of the study drug.

• Participants must have a Young Mania Rating Scale (YMRS) score of ≥ 20 at Screeningand at Baseline.

• Participants must have a Clinical Global Impressions-Bipolar (CGI-BP) ≥ 4 atScreening and at Baseline.

Exclusion Criteria:

• Participants must not have any primary Diagnostic and Statistical Manual of MentalDisorders (5th Edition, Text Revision) (DSM-5-TR) disorder, other than BP-I withmania or mania with mixed features within 12 months before screening, including BP-Iwith depression (for previous 3 months only), BP-II disorder, major depressivedisorder, and primary psychotic disorder, with the exception of mild anxietydisorders.

• Participants must not have a primary diagnosis of BP-I with rapid cycling (≥ 4distinct mood episodes in one year).

• Participants must not have a DSM-5-TR diagnosis of moderate to severe substance usedisorder (except tobacco use disorder) within the 12 months before screening, orcurrent use as determined by urine toxicology screen or alcohol test.

• Participants must not be at risk for suicidal behavior at screening or the baselinevisit as determined by the Investigator's clinical assessment and theColumbia-Suicide Severity Rating Scale (C-SSRS).

• Participants must not have a history of irritable bowel syndrome (with or withoutconstipation) or serious constipation requiring treatment within the last 6 months.

• Participants must not have a history or high risk of urinary retention, gastricretention, or untreated narrow-angle glaucoma.

• Other protocol-defined Inclusion/Exclusion criteria apply.