Safety and Tolerability of Zelquistinel in Normal Human Volunteers

March 10, 2026 updated by: Syndeio Biosciences, Inc

A Phase 1, Single Ascending Dose Study to Evaluate the Safety, Tolerability, and Pharmacokinetics of AGN-241751 After Oral Administration in Healthy Volunteers

To evaluate the safety and tolerability of single ascending doses of zelquistinel in normal human volunteers

Study Overview

Status

Status

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

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

Single ascending dose (SAD), double-blind placebo-controlled study in normal human volunteers.

Secondary objectives:

To evaluate the pharmacokinetics (PK) and eeg biomarker of target engagement of zelquistinel following increasing single doses of zelquistinel.

Zelquistinel or Placebo: Dose/Mode of Administration: Single dose; oral

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 (Actual)

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.
68

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.
  • Phase 1

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

18 years to 45 years (Adult)

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Agree to effective method of birth control
  • If female, negative pregnancy test at screening and Day -1
  • Nonsmoking at least 2 years
  • BMI 18-30
  • Supine pulse rate 30-100

Exclusion Criteria:

  • Known hypersensitivity to NMDA receptor drugs
  • clinically significant disease in any body system
  • QTcF > 430 ms in males, >450 ms in females
  • positive test for hepatitis B or C
  • abnormal liver function tests on Day -1
  • History of alcohol or other substance abuse during the previous 5 years
  • Positive drug screen at screening or Day -1
  • Taken any medication within the past 14 days

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: Triple

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.
Placebo Comparator: Placebo
Placebo tablet, PO, Single Dose with 28 day follow up
Drug: Placebo
Placebo
Experimental: 100 microgram zelquistinel
zelquistinel, 100 microgram tablet, PO, Single Dose with 28 day follow up
Drug: zelquistinel
Single dose of zelquistinel
Experimental: 1 mg zelquistinel
zelquistinel, 1 mg tablet, PO, Single Dose with 28 day follow up
Drug: zelquistinel
Single dose of zelquistinel
Experimental: 3 mg zelquistinel
zelquistinel, 3 mg tablet, PO, Single Dose with 28 day follow up
Drug: zelquistinel
Single dose of zelquistinel
Experimental: 10 mg zelquistinel
zelquistinel, 10 mg tablet, PO, Single Dose with 28 day follow up
Drug: zelquistinel
Single dose of zelquistinel
Experimental: 25 mg zelquistinel
zelquistinel, 25 mg tablet, PO, Single Dose with 28 day follow up
Drug: zelquistinel
Single dose of zelquistinel
Experimental: 50 mg zelquistinel
zelquistinel, 50 mg tablet, PO, Single Dose with 28 day follow up
Drug: zelquistinel
Single dose of zelquistinel
Experimental: 100 mg zelquistinel
zelquistinel, 100 mg tablet, PO, Single Dose with 28 day follow up
Drug: zelquistinel
Single dose of zelquistinel
Experimental: 1 mg zelquistinel with CSF collection
zelquistinel, 1 mg tablet, PO, Single Dose with 28 day follow up, with CSF collection
Drug: zelquistinel
Single dose of zelquistinel
Experimental: 10 mg zelquistinel with CSF collection
zelquistinel, 10 mg tablet, PO, Single Dose with 28 day follow up, with CSF collection
Drug: zelquistinel
Single dose of zelquistinel

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
Treatment emergent adverse events
Time Frame: 28 days
through study completion
28 days

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
Pharmacokinetics, maximum plasma concentration
Time Frame: 24 hours
maximum plasma concentration
24 hours
Pharmacokinetics, time to maximum plasma concentration
Time Frame: 24 hours
time to maximum plasma concentration
24 hours
Pharmacokinetics, area under the curve for plasma concentration
Time Frame: 72 hours
area under the curve, plasma calculated 0-infinity
72 hours

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.
Syndeio Biosciences, Inc

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 Chair: Aaron Koenig, MD, Syndeio Biosciences

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.
December 9, 2016

Primary Completion (Actual)

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.
December 21, 2017

Study Completion (Actual)

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.
December 21, 2017

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).
July 18, 2021

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.
July 28, 2021

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.
July 29, 2021

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.
March 12, 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.
March 10, 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.
July 1, 2021

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.
  • 3125-101-009

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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