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Long-term safety of KarXT and KarX-EC in adolescents with schizophrenia or autism-related irritability

A Phase 3 Multicenter, Open-label Study to Assess the Long-term Safety and Tolerability of KarXT in Adolescents (13 to 17 Years of Age) With Schizophrenia and KarXT+KarX-EC in Children and Adolescents (5 to 17 Years of Age) With Irritability Associated With Autism Spectrum Disorder

Phase 3 Interventional Karuna Therapeutics, Inc., a Bristol Myers Squibb company · NCT07424404

This trial will test whether taking KarXT (for schizophrenia) or KarX-EC (for autism-related irritability) is safe and tolerable for adolescents over the long term.

Quick facts

PhasePhase 3
Study typeInterventional
Enrollment400 (estimated)
Ages5 Years to 17 Years
SexAll
SponsorKaruna Therapeutics, Inc., a Bristol Myers Squibb company Industry-sponsored
Locations59 sites (Anaheim, California and 58 other locations)
Trial IDNCT07424404 on ClinicalTrials.gov

What this trial studies

This Phase 3 extension enrolls adolescents who completed the double-blind treatment periods of the parent trials (CN0120020, CN0120044, or CN0120045) to continue on KarXT or KarX-EC and be followed for long-term safety and tolerability. Participants will be monitored regularly for adverse events, vital signs, ECG findings, and psychiatric status. Enrollment excludes those with clinically significant abnormal physical/ECG findings or who are judged to be at high risk of violent behavior or suicide. The goal is to gather extended safety data to inform ongoing use in adolescent populations.

Who should consider this trial

Good fit: Adolescents who completed the double-blind period of the parent Phase 3 trials without concerning adverse events and who are not judged to be at high risk for violence or suicide are eligible.

Not a fit: Patients with significant risk of violence or suicide, or with clinically significant abnormal physical exam or ECG findings at the end of the prior treatment, are unlikely to benefit or be eligible for continued treatment in this protocol.

Why it matters

Potential benefit: If successful, the trial could show these treatments are safe for longer-term use in adolescents, supporting longer treatment options and clearer risk information.

How similar studies have performed: Shorter-term trials of KarXT in adults have shown promising efficacy and tolerability signals, but long-term safety data in adolescents remain limited.

Eligibility criteria

Show full inclusion / exclusion criteria 
Inclusion Criteria

\- Participants must have completed the double-blind treatment period (ie, Visit 8) of Study CN0120020 or the double-blind treatment period (ie, Week 8) of Study CN0120044 or CN0120045, without an adverse event (AE) that, in the investigator's opinion, may indicate an unacceptable safety risk.

Exclusion Criteria

* Participants must not have a significant risk of committing violent acts, serious self-harm, or attempting suicide based on history or routine psychiatric status examination, or those who are homicidal or are considered to be a high risk to others, or who have an answer of "Yes" on Questions 4 or 5 on the suicidal ideation section of the "Since Last Visit" version of the C-SSRS at baseline (Visit 1). Nonsuicidal, self-injurious behavior is not exclusionary.
* Participants must not have any clinically significant abnormality including any finding(s) from the physical examination, vital signs, ECG at the end of treatment visit of Study CN0120020, CN0120044, or CN0120045 that the investigator, in consultation with the Sponsor Medical Monitor, would jeopardize the safety of the participant.
* Participants must not have either a systolic blood pressure (sBP) or diastolic blood pressure (dBP) meeting criteria for stage 2 hypertension (HTN), regardless of the presence or absence of symptoms.
* Other protocol-defined Inclusion/Exclusion criteria apply.

Where this trial is running

Anaheim, California and 58 other locations

+9 more sites — see ClinicalTrials.gov for the full list.

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
View on ClinicalTrials.gov → Find more trials like this →
Conditions SchizophreniaAutism-Related Irritability
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.