A Brain Imaging Study to Assess the Binding of MSP-2020 to Serotonin 5-HT2A Receptors in Healthy Male Adults

August 14, 2026 updated by: Otsuka Pharmaceutical Development & Commercialization, Inc.

A Phase 1, Open-label, Positron Emission Tomography (PET) Trial to Measure Serotonin 5-HT2A Receptor Occupancy Following Single Oral Doses of MSP-2020 in Healthy Male Adults

This study is to see how well MSP-2020 attaches to specific targets in the brain called serotonin type 2A receptors (5-HT2AR). This study will also look at how much of the study drug (and its metabolite) is in the blood and how long the study drug stays in the blood, as well as the safety of MSP 2020.

Study Overview

Status

Status

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

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.
8

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 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 Locations

  • United Kingdom
      • London, United Kingdom
        • HMR Hammersmith Medicines Research Ltd.

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. Able to stay in the CRU for up to 4 days.
  2. Body mass index (BMI) between 18.0 to 32.0 kg/m2 (inclusive).
  3. In good health as determined by: a. Medical history; b. Physical and neurological examination; c. Concomitant medications; d. ECG; e. Screening echocardiogram; f. Serum chemistry, urinalysis, haematology, coagulation, and serology (HIV screen, HBsAg, and anti-HCV) tests.

Exclusion Criteria

  1. In first-degree relatives, a history of any schizophrenia-spectrum disorder, psychotic disorder, or bipolar and related disorders.
  2. History of allergy to tracer [11C]CIMBI-36.
  3. MRI incompatibility due to implants including but not limited to pacemaker, artificial joints, or non-removable body piercings, and/or other contraindications for MRI such as claustrophobia, metal objects/fragments, or fragments in the head or body that would present a risk during the MRI scanning procedure, or have worked with ferrous metals (eg, welding), or have motor problems that prevent the participant from lying still for the MRI.
  4. Pathological MRI findings that would preclude from trial participation.
  5. History of prior radiation exposure for research purposes such that participation in this trial would result in an ionising radiation exposure of > 10 mSv within a year (12 months) of the first PET scan that would cause the participant to exceed the yearly dose limit.
  6. Have a negative modified Allen test at screening.
  7. Contraindications to radial arterial cannula (including but not limited to cellulitis or other infections over the radial artery, absence of palpable radial artery pulse, or a clinically significant abnormal coagulation profile).
  8. Clinically significant abnormality in past medical history, or at the screening physical examination, that in the investigator's or sponsor's opinion may place the participant at risk or interfere with outcome variables including absorption, distribution, metabolism, and excretion of drug. This includes, but is not limited to, history of or concurrent cardiac, hepatic, renal, neurologic, endocrine, gastrointestinal, respiratory, haematologic, dermatologic, and immunologic disease.
  9. History of alcohol and/or substance use disorder within the last 24 months according to the Diagnostic Statistical Manual of Mental Disorders and in past medical history or in the investigator's opinion, or intake of > 21 units of alcohol weekly, and the inability to refrain from alcohol use from 48 hours before screening and within 72 hours prior to dosing until discharge from the CRU on Day 2. One unit is equivalent to 1 (25 mL) measure of 40% spirits. For reference, one 330 mL bottle of 5% beer contains 1.7 units and a standard (175 mL) glass of 12% wine contains 2.1 units.

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: N/A
  • Interventional Model: Sequential 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: MSP-2020 Oral Administration
Participants will receive a single dose of MSP-2020 on Day 1.
Drug: MSP-2020
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
Time Frame
Percent Change in Specific Binding of [11C]CIMBI-36 from Baseline and EC50 Using Cortical Regions [11C]CIMBI-36 BPND
Time Frame: Up to Day 2
Up to Day 2
PK Plasma Concentration of MSP-2020 and its Metabolite
Time Frame: Up to Day 2
Up to Day 2
Maximum (peak) Plasma Concentration of MSP-2020 and its Metabolite
Time Frame: Up to Day 2
Up to Day 2
Time to Maximum (peak) Plasma Concentration of MSP-2020 and its Metabolite
Time Frame: Up to Day 2
Up to Day 2
Half-life (t1/2) of MSP-2020 and its metabolite
Time Frame: Up to Day 2
Up to Day 2
Area under the concentration-time curve (AUCt) of MSP-2020 and its metabolite
Time Frame: Up to Day 2
Up to Day 2

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
Concentration of the metabolite at which 50% of the 5-HT2A receptors are occupied, as measured by PET imaging
Time Frame: Up to Day 2
Up to Day 2
Number of Participants With Adverse Events (AEs)
Time Frame: Up to Day 15
Up to Day 15
Number of Participants With Potentially Clinically Significant Changes in Vital Signs
Time Frame: Up to Day 2
Up to Day 2
Number of Participants With Potentially Clinically Significant Changes in Electrocardiogram (ECG)
Time Frame: Up to Day 2
Up to Day 2
Number of Participants With Potentially Clinically Significant Changes in Laboratory Tests
Time Frame: Up to Day 15
Up to Day 15
Number of Participants With Potentially Clinically Significant Changes in Physical and Neurological Examinations
Time Frame: Up to Day 15
Up to Day 15
Number of Participants With Suicidality on Columbia-Suicide Severity Rating Scale (C-SSRS)
Time Frame: Up to Day 15
Up to Day 15
Change from baseline in relevant scales
Time Frame: Up to Day 2
Up to Day 2

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.

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Helpful Links

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.
January 15, 2026

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.
July 10, 2026

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.
July 17, 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).
December 19, 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 6, 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 9, 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.
August 18, 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.
August 14, 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.
August 1, 2026

More Information

Terms related to this study

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.
  • 358-201-00002

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

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

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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