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Study of trospium chloride and xanomeline tartrate (KarXT) for treating manic episodes in adults with bipolar I disorder

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What is this trial about?

A plain-language summary of the goals, design and what participants do

This study focuses on Bipolar-I Disorder, specifically during periods of mania or mania with mixed features. During manic episodes, people may experience unusually high energy levels, reduced need for sleep, and potentially risky behavior. The study will test a medication called KarXT, which contains two active substances: trospium chloride and xanomeline tartrate. Some participants will receive KarXT capsules while others will receive a placebo.

The purpose of this research is to determine if KarXT is effective in reducing the severity and symptoms of mania in people with Bipolar-I Disorder. The study medication or placebo will be taken orally as capsules for a period of three weeks while participants are in the hospital. During this time, participants will not take other medications used to treat mental health conditions.

Throughout the study, healthcare providers will monitor participants' symptoms and overall health. They will use various assessment tools to measure changes in manic symptoms and daily functioning. The study will also track any side effects that participants may experience during the treatment period.

The research process

The trial runs in 5 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Initial evaluation

    You will undergo a comprehensive psychiatric evaluation to confirm the diagnosis of Bipolar-I disorder.

    Your current manic episode must be no longer than 3 weeks in duration.

    The evaluation includes completing two assessment scales: the Young Mania Rating Scale (YMRS) and Clinical Global Impressions-Bipolar (CGI-BP).

  2. Step 2

    Medication discontinuation period

    Any current psychiatric medications will need to be discontinued over a period of up to 14 days before starting the study medication.

    This process will take place during hospitalization for your safety.

  3. Step 3

    Treatment initiation

    You will be randomly assigned to receive either KarXT capsules or placebo capsules (capsules without active medication).

    The medication will be taken by mouth.

    Neither you nor your healthcare providers will know which treatment you are receiving.

  4. Step 4

    Treatment period

    The treatment period lasts for 3 weeks.

    During this time, you will remain in the hospital.

    Your manic symptoms will be regularly evaluated using the YMRS scale.

    Your overall functioning will be assessed using the CGI-BP scale.

    Additional assessments will be performed to monitor your safety and any side effects.

  5. Step 5

    Final evaluation

    At the end of week 3, a final assessment will be conducted.

    The evaluation will include the same scales used at the beginning of the study.

    Any side effects or health changes that occurred during the study will be documented.

Who can join the trial?

8 criteria

  • Must be between 18 and 65 years old when signing the consent form
  • Must have been diagnosed with Bipolar-I disorder (a mental health condition that causes extreme mood swings) confirmed by a psychiatric evaluation and special diagnostic interview
  • Must be currently experiencing an acute manic episode (a period of extremely elevated mood, energy and activity) that started within the last 3 weeks
  • Must require hospital admission due to worsening of manic symptoms
  • Must stop taking all psychiatric medications at least 14 days before starting the study medication
  • Must score 20 or higher on the Young Mania Rating Scale (a test that measures severity of manic symptoms) during initial evaluations
  • Must score 4 or higher on the Clinical Global Impressions Scale (a test that measures illness severity) during initial evaluations
  • Both men and women can participate in the study

Who cannot join the trial?

15 criteria

  • People younger than 18 or older than 65 years of age
  • Current diagnosis of substance abuse or dependence within the past 3 months
  • History of severe heart conditions or uncontrolled high blood pressure
  • Pregnant or breastfeeding women
  • Current use of medications that could interact with the study drug
  • History of psychotic disorders (conditions that affect how a person thinks, feels and behaves)
  • Severe kidney or liver problems
  • History of seizures or epilepsy
  • Participation in another clinical trial within the past 30 days
  • Unstable medical conditions that could interfere with the study
  • History of not responding to similar treatments
  • Presence of active suicidal thoughts or behaviors
  • Unable to provide informed consent
  • History of severe allergic reactions to similar medications
  • Significant abnormal laboratory test results
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Investigated drugs

KarXT is a medication being studied for treating manic episodes in people with Bipolar I Disorder. It is an investigational drug that combines two substances that work together to help reduce symptoms of mania. This medication works by affecting certain chemical signals in the brain that are involved in mood regulation.

What is already known about the treatment

KarXT - An investigational medication administered orally that is currently undergoing Phase 3 clinical trials for the treatment of manic episodes in Bipolar I Disorder (BP-I). The drug represents a novel therapeutic approach targeting the central nervous system, specifically designed to reduce the severity and symptoms of mania in patients with BP-I mania or mania with mixed features. While the complete mechanism of action is still being studied in clinical trials, KarXT belongs to a new class of therapeutic agents being evaluated for psychiatric conditions, with its efficacy and safety profile currently being assessed through randomized, double-blind, placebo-controlled studies.

Investigated diseases

Bipolar I Disorder with Mania - A mental health condition characterized by episodes of extreme mood elevation known as mania. During manic episodes, individuals experience unusually high energy levels, reduced need for sleep, racing thoughts, and increased activity levels. People may engage in risky behaviors, have grandiose beliefs, or show poor judgment during these episodes. Some patients experience mixed features, where symptoms of mania occur alongside symptoms of depression. Mania episodes typically last at least a week if left untreated and can significantly impact daily functioning.
Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2024-520195-94-00Protocol codeCN012-0037Estimated enrolment276 patientsSponsorBristol-Myers Squibb Services Unlimited Company

sourced from the EU Clinical Trials Register and site verification

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