Single and Multiple Ascending Doses of NTX-253 in Healthy Participants and Participants With Stable Schizophrenia

January 7, 2026 updated by: Neurosterix

A First in Human, Phase 1/1b Study of Single and Multiple Ascending Dosing Administration of NTX110253 in Healthy Participants and Participants With Stable Schizophrenia

This study will assess the safety, tolerability, and pharmacokinetics of NTX-253 following oral administration in both healthy adult participants as well as adult participants with stable schizophrenia.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

This study will assess the safety, tolerability, and pharmacokinetics of NTX-253 following oral administration in both healthy adult participants as well as adult participants with stable schizophrenia. NTX-253 is an investigational drug being developed for the treatment of schizophrenia. The study will consist of a single ascending dose (SAD - Part 1a) phase which will include a food effect cohort, and a cerebrospinal fluid (CSF - Part 1b) cohort in healthy volunteers. Participants will receive a single dose of either oral NTX-253 or placebo. The multiple ascending dose (MAD - Part 2) phase will follow. In Part 2, participants will be dosed for 10 consecutive days with either NTX-253 or placebo. Each phase will include sequential escalating doses in healthy volunteers. Two cohorts in the MAD phase will include stable schizophrenic adult participants who have had antipsychotic medication withdrawn for up to 8 days prior to dosing with NTX-253.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
73

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Early Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

  • United States
    • California
      • Los Alamitos, California, United States, 90720
        • Recruiting
        • Collaborative Neuroscience Research, LLC - CenExel
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult

Accepts Healthy Volunteers

Yes

Description

Primary Inclusion Criteria:

  • Male or non-pregnant, non-lactating female participants, ages 18-55 who are not of childbearing potential, with a truly abstinent lifestyle, or agrees to use medically acceptable forms of birth control
  • Part 1 a/b, Part 2 Cohort 7 only: Body mass index (BMI) within the range ≥18.0 to ≤30.0 kg/m2
  • Participants in the food effect cohort must be willing to eat a single high fat breakfast
  • (Part 2 only): Stable schizophrenia participants (schizophrenia cohorts only)
  • Body mass index (BMI) within the range ≥17.5 to ≤36.0 kg/m2
  • Positive and Negative Syndrome Scale (PANSS) total score <80 at screening

Primary Exclusion Criteria:

  • (Part 1a/b, Part 2 Healthy): History of or current clinically significant medical or mental illness
  • Cancer diagnosis/treatment in the past 7 years
  • Acute or chronic gastrointestinal conditions that would interfere with drug tolerance or absorption
  • Any clinically significant, abnormal 12 lead ECG
  • Part 2: Any primary DSM-5TR disorder other than schizophrenia
  • Participants with schizophrenia who are considered resistant/refractory to antipsychotic treatment by history; history of clozapine use.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: NTX-253 Part 1a
Participants will be assigned to receive one of multiple single ascending daily oral doses of NTX-253
Drug: NTX-253
Oral Capsule
Experimental: Placebo Part 1a
Participants will be assigned to receive one of multiple single ascending daily oral doses of placebo
Drug: Placebo
Oral capsule
Experimental: NTX-253 Part 1b
Participants will receive the maximum tolerated single oral dose of NTX-253
Drug: NTX-253
Oral Capsule
Experimental: NTX-253 Part 2
Participants will be assigned to receive one of multiple ascending oral daily doses of NTX-253 for 10 days
Drug: NTX-253
Oral Capsule
Experimental: Placebo Part 2
Participants will be assigned to receive one of multiple ascending daily oral doses of placebo for 10 days
Drug: Placebo
Oral capsule

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Number of reported Adverse Events
Time Frame: From baseline until Day 8 after a single dose, Day 17 (healthy volunteers) or Day 35 (participants with stable schizophrenia).
Safety and tolerability will be assessed by the incidence and severity of treatment-emergent adverse events.
From baseline until Day 8 after a single dose, Day 17 (healthy volunteers) or Day 35 (participants with stable schizophrenia).
Number of Adverse Events of Special Interest (AESI)
Time Frame: From baseline until Day 8 after a single dose, Day 17 (healthy volunteers) or Day 35 (participants with stable schizophrenia).
Safety and tolerability will be assessed by the incidence and severity of AESIs.
From baseline until Day 8 after a single dose, Day 17 (healthy volunteers) or Day 35 (participants with stable schizophrenia).
Number of dose limiting treatment emergent adverse events (TEAE)
Time Frame: From baseline until Day 8 after a single dose, Day 17 (healthy volunteers) or Day 35 (participants with stable schizophrenia).
Safety and tolerability will be assessed by the incidence and severity of serious or dose limiting TEAEs.
From baseline until Day 8 after a single dose, Day 17 (healthy volunteers) or Day 35 (participants with stable schizophrenia).
Vital Signs: Change in blood pressure
Time Frame: From baseline until Day 8 after a single dose, Day 17 (healthy volunteers) or Day 35 (participants with stable schizophrenia).
Blood pressure measurements
From baseline until Day 8 after a single dose, Day 17 (healthy volunteers) or Day 35 (participants with stable schizophrenia).
Vital Signs: Change in temperature
Time Frame: From baseline until Day 8 after a single dose, Day 17 (healthy volunteers) or Day 35 (participants with stable schizophrenia).
Oral temperature measurement
From baseline until Day 8 after a single dose, Day 17 (healthy volunteers) or Day 35 (participants with stable schizophrenia).
Vital Signs: Change in respiratory rate
Time Frame: From baseline until Day 8 after a single dose, Day 17 (healthy volunteers) or Day 35 (participants with stable schizophrenia).
Respiratory rate (number of breaths per minute) measurements
From baseline until Day 8 after a single dose, Day 17 (healthy volunteers) or Day 35 (participants with stable schizophrenia).
Vital Signs: Change in heart rate
Time Frame: From baseline until Day 8 after a single dose, Day 17 (healthy volunteers) or Day 35 (participants with stable schizophrenia).
Pulse measurements.
From baseline until Day 8 after a single dose, Day 17 (healthy volunteers) or Day 35 (participants with stable schizophrenia).
Change in physical examination
Time Frame: From baseline until Day 8 after a single dose, Day 17 (healthy volunteers) or Day 35 (participants with stable schizophrenia).
Investigator will perform complete physical exam and document any clinically significant conditions.
From baseline until Day 8 after a single dose, Day 17 (healthy volunteers) or Day 35 (participants with stable schizophrenia).
Clinical Laboratory Tests
Time Frame: From baseline until Day 8 after a single dose, Day 17 (healthy volunteers) or Day 35 (participants with stable schizophrenia).
Hematology, serum chemistry, urinalysis, and coagulation tests.
From baseline until Day 8 after a single dose, Day 17 (healthy volunteers) or Day 35 (participants with stable schizophrenia).

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Maximum observed plasma concentration (Cmax) [Pharmacokinetics]
Time Frame: From baseline until up to 168 hours after a single dose, or until up to 168 hours after the last dose in the multiple dose cohorts.

Samples will be collected periodically until:

  • 72 hours after a single dose with optional samples collected at 96, 120, 144, and 168 post-dose.
  • 72 hours after multiple doses with optional samples collected at 96, 120, 144, and 168 hours after the last dose.
From baseline until up to 168 hours after a single dose, or until up to 168 hours after the last dose in the multiple dose cohorts.
Time of Cmax (tmax) [Pharmacokinetics]
Time Frame: From baseline until up to 168 hours after a single dose, or until up to 168 hours after the last dose in the multiple dose cohorts.

Samples will be collected periodically until:

  • 72 hours after a single dose with optional samples collected at 96, 120, 144, and 168 post-dose.
  • 72 hours after multiple doses with optional samples collected at 96, 120, 144, and 168 hours after the last dose.
From baseline until up to 168 hours after a single dose, or until up to 168 hours after the last dose in the multiple dose cohorts.
Apparent terminal half-life (t1/2)
Time Frame: From baseline until up to 168 hours after a single dose, or until up to 168 hours after the last dose in the multiple dose cohorts.

Samples will be collected periodically until:

  • 72 hours after a single dose with optional samples collected at 96, 120, 144, and 168 post-dose.
  • 72 hours after multiple doses with optional samples collected at 96, 120, 144, and 168 hours after the last dose.
From baseline until up to 168 hours after a single dose, or until up to 168 hours after the last dose in the multiple dose cohorts.
Amount of unchanged drug excreted in urine (Ae) [urinary excretion)
Time Frame: From baseline until 72 hours after a single dose, or until the last dosing on Day 10 in the multiple dose cohort.
Samples will be collected in select cohorts from baseline until 72 hours after a single dose, or at baseline and on the last dosing day after multiple dose administrations.
From baseline until 72 hours after a single dose, or until the last dosing on Day 10 in the multiple dose cohort.
Percent of dose excreted as unchanged drug in urine (Ae%) [urinary excretion]
Time Frame: From baseline until 72 hours after a single dose, or until the last dosing on Day 10 in the multiple dose cohort.
Samples will be collected in select cohorts from baseline until 72 hours after a single dose, or at baseline and on the last dosing day after multiple dose administrations.
From baseline until 72 hours after a single dose, or until the last dosing on Day 10 in the multiple dose cohort.
Renal clearance (Clr) [urinary excretion]
Time Frame: From baseline until 72 hours after a single dose, or until the last dosing on Day 10 in the multiple dose cohort.
Samples will be collected in select cohorts from baseline until 72 hours after a single dose, or at baseline and on the last dosing day after multiple dose administrations.
From baseline until 72 hours after a single dose, or until the last dosing on Day 10 in the multiple dose cohort.
Maximum observed CSF concentration (Cmax, CSF) [Pharmacokinetics]
Time Frame: From baseline until 12 hours after a single dose.
CSF samples will be collected at periodic intervals until 12 hours after a single dose in a single dose CSF cohort.
From baseline until 12 hours after a single dose.
Time corresponding to Cmax (Tmax, CSF) [Pharmacokinetics]
Time Frame: From baseline until 12 hours after a single dose.
CSF samples will be collected at periodic intervals until 12 hours after a single dose in a single dose CSF cohort.
From baseline until 12 hours after a single dose.
QT/QTc potential interval prolongation and plasma concentration
Time Frame: From baseline until 72 hours post-dose in the single dose cohorts, then from baseline until Day 13 in the multiple dose cohorts.

Electrocardiograms (ECGs) will be collected to assess the potential for QT/QTc interval prolongation and ΔQTc as measured by:

• Change from baseline in cardiac measurements
From baseline until 72 hours post-dose in the single dose cohorts, then from baseline until Day 13 in the multiple dose cohorts.

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Neurosterix

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Study Director: Doug Feltner, MD, Neurosterix

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
October 3, 2025

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
May 1, 2026

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
May 1, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
November 14, 2025

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
January 7, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
January 15, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
January 15, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
January 7, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
January 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • NTX-0253-101

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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