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

NCT07305779 | Completed Phase 1 FDA Drug

• 1 other identifier: 384-201-00004
• Study Type: interventional
• Target: 12
• Locations: 1 country
• Sites: 1

Brief Summary

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.

Conditions

Schizophrenia

Keywords

Mental Health Conditions; Schizophrenia

Outcome Measures

Primary Outcomes (4)

• Maximum Observed Concentration (Cmax) of SEP-380135 and its Metabolites

  Up to Day 11

• Area Under the Curve from Time Zero to Last Measurable Concentration (AUC0-t) of SEP-380135 and its Metabolites

  Up to Day 11

• Area Under the Curve from Time Zero to Infinity (AUCinfinity) of SEP-380135 and its Metabolites

  Up to Day 11

• Time to Maximum Concentration (Tmax) of SEP-380135 and its Metabolites

  Up to Day 11

Secondary Outcomes (7)

• Number of Participants With Treatment Emergent Adverse Events (TEAEs)

  Up to 2 months

• Number of Participants With Potentially Clinically Significant Changes in Vital Signs

  Up to 2 months

• Number of Participants With Potentially Clinically Significant Changes in Electrocardiogram (ECG) Parameters

  Up to 2 months

• Number of Participants With Potentially Clinically Significant Changes in Physical Examinations

  Up to 2 months

• Number of Participants With Potentially Clinically Significant Changes in Neurological Examinations

  Up to 2 months

Study Arms (1)

SEP-380135 + Quinidine Gluconate

EXPERIMENTAL

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; Drug: Quinidine Gluconate

Interventions

Quinidine Gluconate DRUG

Oral extended-release (ER) tablets.

SEP-380135 + Quinidine Gluconate

SEP-380135 DRUG

Oral capsules.

SEP-380135 + Quinidine Gluconate

Eligibility Criteria

• Age: 18 Years - 55 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Male or female participants between 18 and 55 years of age (inclusive) at time of consent
• Body mass index from 18.0 to 32.0 kilograms per square meter (kg/m\^2) (inclusive).
• In good health as determined by:
• Medical history
• Physical examination
• Vital signs
• Neurological examination
• Electrocardiogram
• Serum chemistry, lipid panel, thyroid panel, coagulation panel, urinalysis, hematology, and serology tests (from screening visit).
• 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.
• 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.

You may not qualify if:

• Have taken an investigational drug within 30 days or 5 half-lives, if known, (whichever is longer) prior to screening.
• Have had previous exposure to SEP-380135.
• Are currently participating in another clinical trial.
• Attempted suicide within 12 months prior to screening.
• 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.
• In the opinion of the investigator, should not participate in the trial.

Sponsors & Collaborators

• Otsuka Pharmaceutical Development & Commercialization, Inc.: lead

Study Sites (1)

Dr. Vince Clinical Research

Overland Park, Kansas, 66212, United States

Location

MeSH Terms

Conditions

Schizophrenia

Interventions

quinidine gluconate

Condition Hierarchy (Ancestors)

Schizophrenia Spectrum and Other Psychotic Disorders; Mental Disorders

Study Design

• Study Type: interventional
• Phase: phase 1
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: December 12, 2025
• First Posted: December 26, 2025
• Study Start: March 7, 2025
• Primary Completion: May 3, 2025
• Study Completion: May 3, 2025
• Last Updated: January 15, 2026

Record last verified: 2025-11

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)