A Trial to Test the Effects of Other Drugs on SEP-380135 in Healthy Men and Women

January 13, 2026 updated by: Otsuka Pharmaceutical Development & Commercialization, Inc.

A Phase 1, Open-label, Single-sequence Pharmacokinetic Trial to Assess the Effect of a Single Oral Dose of SEP-380135 on the Potential for Cytochrome P4502D6 Mediated Drug-drug Interactions in Healthy Adults

The purpose of this study is to assess the effect of cytochrome P450 isoenzyme 2D6 (CYP2D6) inhibition by quinidine on the pharmacokinetic (PK) parameters of a single dose SEP-380135 in healthy adult participants.

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.

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.
12

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

Contacts and Locations

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

Study Locations

  • United States
    • Kansas
      • Overland Park, Kansas, United States, 66212
        • Dr. Vince Clinical Research

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

Inclusion Criteria:

  1. Male or female participants between 18 and 55 years of age (inclusive) at time of consent
  2. Body mass index from 18.0 to 32.0 kilograms per square meter (kg/m^2) (inclusive).

  3. In good health as determined by:

    1. Medical history
    2. Physical examination
    3. Vital signs
    4. Neurological examination
    5. Electrocardiogram
    6. Serum chemistry, lipid panel, thyroid panel, coagulation panel, urinalysis, hematology, and serology tests (from screening visit).
  4. Willing to stay in the clinic for the required period (i.e., to be hospitalized for 10 days) and willing to be contacted for the safety follow-up telephone call.
  5. Ability to provide written, informed consent prior to initiation of any trial-related procedures, and ability, in the opinion of the Principal Investigator, to comply with all the requirements of the trial.

Exclusion Criteria:

  1. Have taken an investigational drug within 30 days or 5 half-lives, if known, (whichever is longer) prior to screening.
  2. Have had previous exposure to SEP-380135.
  3. Are currently participating in another clinical trial.
  4. Attempted suicide within 12 months prior to screening.
  5. A history of sick sinus syndrome, first-, second-, or third-degree atrioventricular block, myocardial infarction, New York Heart Association Class II-IV heart failure, cardiomyopathy, pulmonary congestion, cardiac arrhythmia, prolonged QT interval, congenital long QT syndrome, family history of long QT, or moderate to severe hypokalemia. A participant with non-clinically significant ECG abnormalities at screening and check-in requires approval from the medical monitor and the sponsor's physician.
  6. In the opinion of the investigator, should not participate in the trial.

Note: Other protocol-specified inclusion/exclusion criteria may apply.

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: Non-Randomized
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

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: SEP-380135 + Quinidine Gluconate
Participants receive SEP-380135 alone on Day 1, followed by administration of quinidine gluconate beginning on Day 6. On Day 7, SEP-380135 is coadministered with quinidine gluconate. Quinidine gluconate dosing continues from Day 8 to Day 10.
Drug: SEP-380135
Oral capsules.
Drug: Quinidine Gluconate
Oral extended-release (ER) tablets.

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
Time Frame
Maximum Observed Concentration (Cmax) of SEP-380135 and its Metabolites
Time Frame: Up to Day 11
Up to Day 11
Area Under the Curve from Time Zero to Last Measurable Concentration (AUC0-t) of SEP-380135 and its Metabolites
Time Frame: Up to Day 11
Up to Day 11
Area Under the Curve from Time Zero to Infinity (AUCinfinity) of SEP-380135 and its Metabolites
Time Frame: Up to Day 11
Up to Day 11
Time to Maximum Concentration (Tmax) of SEP-380135 and its Metabolites
Time Frame: Up to Day 11
Up to Day 11

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
Time Frame
Number of Participants With Treatment Emergent Adverse Events (TEAEs)
Time Frame: Up to 2 months
Up to 2 months
Number of Participants With Potentially Clinically Significant Changes in Vital Signs
Time Frame: Up to 2 months
Up to 2 months
Number of Participants With Potentially Clinically Significant Changes in Electrocardiogram (ECG) Parameters
Time Frame: Up to 2 months
Up to 2 months
Number of Participants With Potentially Clinically Significant Changes in Physical Examinations
Time Frame: Up to 2 months
Up to 2 months
Number of Participants With Potentially Clinically Significant Changes in Neurological Examinations
Time Frame: Up to 2 months
Up to 2 months
Number of Participants With Potentially Clinically Significant Changes in Clinical Laboratory Test Parameters
Time Frame: Up to 2 months
Up to 2 months
Number of Participants With Incidence of Suicidal Behavior, Suicidal Ideation and Suicidality Using the Columbia-Suicide Severity Rating Scale (C-SSRS)
Time Frame: Up to 2 months
Up to 2 months

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.
Otsuka Pharmaceutical Development & Commercialization, Inc.

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.
March 7, 2025

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.
May 3, 2025

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.
May 3, 2025

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).
December 12, 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.
December 12, 2025

First Posted (Estimated)

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.
December 26, 2025

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 13, 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.
November 1, 2025

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.
  • 384-201-00004

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Anonymized individual participant data (IPD) that underlie the results of this study will be shared with researchers to achieve aims pre-specified in a methodologically sound research proposal. Small studies with less than 25 participants are excluded from data sharing.

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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