---
title: Clinical Study on Histamine H3 Receptor Occupancy of TS-091 by PET Examination in Healthy Adult Subjects
nct_id: NCT04631276
overall_status: COMPLETED
phase: PHASE1
sponsor: Taisho Pharmaceutical Co., Ltd.
study_type: INTERVENTIONAL
primary_condition: Healthy Subjects
countries: Japan
canonical_url: "https://parkinsonspathways.com/agent/trials/NCT04631276.md"
clinicaltrials_gov: "https://clinicaltrials.gov/study/NCT04631276"
ct_last_update_post_date: 2025-02-28
last_seen_at: "2026-05-12T06:01:44.785Z"
source: ClinicalTrials.gov (mirrored, no enrichment)
---
# Clinical Study on Histamine H3 Receptor Occupancy of TS-091 by PET Examination in Healthy Adult Subjects

**NCT ID:** [NCT04631276](https://clinicaltrials.gov/study/NCT04631276)

## Key Facts

- **Status:** COMPLETED
- **Phase:** PHASE1
- **Study Type:** INTERVENTIONAL
- **Target Enrollment:** 12
- **Lead Sponsor:** Taisho Pharmaceutical Co., Ltd.
- **Conditions:** Healthy Subjects
- **Start Date:** 2014-12-11
- **Completion Date:** 2015-12-16
- **CT.gov Last Update:** 2025-02-28

## Brief Summary

To evaluate the following items by PET examination in Japanese heathy adult male subjects who received single oral administration of TS-091 in an unblinded manner.

1. Relationship between plasma concentration and H3 receptor-occupancy of TS-091
2. Time course changes in H3 receptor-occupancy of TS-091

## Eligibility

- **Minimum age:** 20 Years
- **Maximum age:** 39 Years
- **Sex:** MALE
- **Healthy Volunteers:** Yes

```
Inclusion Criteria:

Subjects who met all of the following criteria.

* Age: between ≥20 years and \<40 years at the time of providing written consent for participation in the study.
* Body mass index (BMI): ≥18.5 and \<25.0 on the day of screening test.
* Subject who received a prior explanation on the study and was able to understand its content and capable of providing voluntary written consent for participation in the study.
* Other protocol defined inclusion criteria could apply-

Exclusion Criteria:

Subjects who came under any of the following exclusion criteria.

* Subjects who were considered to have some disease and not healthy by the investigator or subinvestigator according to his medical judgment based on the results of screening test
* Subjects with a drug or food allergy or a history thereof.
* Subjects with a significant allergic disposition (e.g. asthma requiring treatment) or a history thereof.
* Subjects with a history of heparin-induced thrombocytopenia.
* Other protocol defined exclusion criteria could apply
```

## Arms

- **Single evaluation of H3 receptor occupancy** (EXPERIMENTAL) — Subjects received single-dose of 0.1, 0.2, 0.4, 1, 2.5, 25 mg TS-091 prior to an evaluation of H3 recepto occupancy
- **Multiple evaluations of H3 receptor occupancy** (EXPERIMENTAL) — Subjects received single-dose of 5, 12.5, 25 mg TS-091 prior to Multiple evaluations of H3 recepto occupancy

## Interventions

- **TS-091** (DRUG) — Subjects received single-dose of 0.1, 0.2, 0.4, 1, 5, 12.5 and 25 mg of TS-091 (tablets or drug substance powder)

## Primary Outcomes

- **H3 receptor occupancy** _(time frame: 2 hours after administration of TS-091)_ — H3 receptor occupancy is calcurated at 2 hours after administration of TS-091.
- **Changes in the H3 receptor occupancy** _(time frame: 2, 6, and 26 hours after administration of TS-091)_ — Changes in the H3 receptor occupancy is calcurated at 2, 6, and 26 hours after administration of TS-091
- **Plasma concentration of unchanged TS-091** _(time frame: 2, 6, and 26 hours after administration of TS-091)_ — Plasma concentration of unchanged TS-091 is calcurated at 2, 6, and 26 hours after administration of TS-091

## Locations (1)

- Taisho Pharmaceutical Co., Ltd selected site, Tokyo, Japan

## Recent Field Changes (last 30 days)

- `status.overallStatus` — added _(2026-05-12)_
- `status.primaryCompletionDate` — added _(2026-05-12)_
- `status.completionDate` — added _(2026-05-12)_
- `status.lastUpdatePostDate` — added _(2026-05-12)_
- `design.phases` — added _(2026-05-12)_
- `design.enrollmentCount` — added _(2026-05-12)_
- `eligibility.criteria` — added _(2026-05-12)_
- `eligibility.minAge` — added _(2026-05-12)_
- `eligibility.maxAge` — added _(2026-05-12)_
- `eligibility.sex` — added _(2026-05-12)_
- `outcomes.primary` — added _(2026-05-12)_
- `armsInterventions.arms` — added _(2026-05-12)_
- `armsInterventions.interventions` — added _(2026-05-12)_
- `sponsor.lead` — added _(2026-05-12)_
- `results.hasResults` — added _(2026-05-12)_
- `locations.taisho pharmaceutical co., ltd selected site|tokyo||japan` — added _(2026-05-12)_

---

*Canonical: https://parkinsonspathways.com/agent/trials/NCT04631276.md*  
*Source data (authoritative): https://clinicaltrials.gov/study/NCT04631276*  
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