Brain imaging to see how MSP-2020 binds serotonin 5-HT2A receptors in healthy men

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 Phase 1 test uses brain scans to see how well MSP-2020 binds to serotonin 5-HT2A receptors in healthy adult men while measuring blood levels and safety.

Quick facts

• Phase: Phase 1
• Study type: Interventional
• Enrollment: 18 (estimated)
• Ages: 23 Years to 55 Years
• Sex: Male
• Sponsor: Otsuka Pharmaceutical Development & Commercialization, Inc. (Industry-sponsored)
• Drugs / interventions: radiation
• Locations: 1 site (London)
• Trial ID: NCT07329621 on ClinicalTrials.gov

What this trial studies

This Phase 1 interventional study enrolls healthy male adults to undergo brain imaging to measure MSP-2020 binding to serotonin 5-HT2A receptors. Participants will receive MSP-2020 and undergo PET/MRI scans, serial blood sampling for drug and metabolite levels, and safety monitoring including ECG and laboratory tests. Volunteers stay in the clinical research unit for up to four days to complete imaging and pharmacokinetic assessments. The trial excludes individuals with MRI contraindications, certain family psychiatric histories, or allergies to the imaging tracer.

Who should consider this trial

Good fit: Healthy adult men with a BMI of 18.0–32.0 who can stay in the clinical research unit for up to four days and meet medical, ECG, echocardiogram, laboratory, and MRI screening criteria.

Not a fit: People seeking direct therapeutic benefit—such as patients with active depressive symptoms, women, individuals with MRI-incompatible implants, allergies to the tracer, or disqualifying psychiatric family history—are unlikely to gain clinical benefit from this imaging and safety-focused study.

Why it matters

Potential benefit: If successful, the results could confirm that MSP-2020 reaches and binds its intended brain target and help determine appropriate dosing for later trials in depression.

How similar studies have performed: PET imaging of 5-HT2A receptor binding is an established method and has been used successfully to show target engagement for related compounds, although MSP-2020 itself is new.

Eligibility criteria

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.

Where this trial is running

London

• HMR Hammersmith Medicines Research Ltd. — London, United Kingdom (Recruiting)

Study contacts

• Study coordinator: Otsuka Call Center

Conditions Incomplete Response - Major Depressive Disorder