Metabolism of Prostaglandin D2Early Phase 1NCT04464070
Pathways of Eicosanoid Metabolism
A Early Phase 1 study testing niacin, aspirin and PGD2 in people with Metabolism of Prostaglandin D2, run by Vanderbilt University at 1 site in United States.
Trial summary
Prostaglandins are important signaling compounds formed from arachidonic acid. The enzymes that form prostaglandins, cyclooxygenase-1 and -2 are the targets of non-steroidal anti-inflammatory drugs (NSAIDs). Because prostaglandins are very unstable in the body, they can not be measured directly. Read more about this study
- Who is it for?
- Ages 18 to 65 yearsHealthy volunteers can take part
- Conditions the study is for
- Metabolism of Prostaglandin D2
- What is being tested?
- niacin, aspirin and PGD2
- Type of treatment
- Pill or oral medicine, Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 10 participants
- Where
- 1 siteUnited States
- Study dates
- 15 Aug 2020to 31 Aug 2027
- Phase
- Early Phase 1
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 65 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Normal, healthy volunteers not currently taking any medication.
Who cannot join
- Use of anti-inflammatory/over-the-counter pain medications (NSAIDs) up to 2 weeks prior to study.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
About this study
Official title: Novel Pathways of Eicosanoid Metabolism
Prostaglandins are important signaling compounds formed from arachidonic acid. The enzymes that form prostaglandins, cyclooxygenase-1 and -2 are the targets of non-steroidal anti-inflammatory drugs (NSAIDs). Because prostaglandins are very unstable in the body, they can not be measured directly. Instead, their metabolites are isolated from urine or blood and quantified as markers of formation of the parent, active compounds.
The investigators are testing the hypothesis that there is a previously unrecognized metabolic pathway between two prostaglandins. The investigators hypothesize that prostaglandin D2 (PGD2), in addition to its known metabolism to PGD-M, is also metabolized to 11-dehydro-thromboxane B2 (11-dehydro-TxB2).
Read the detailed description
The objective of this study is to determine whether PGD2 is metabolized to 11-dehydro-TxB2 in humans. Because the levels of PGD2 and its metabolite, PGD-M, are low in human urine, the investigators will use the model of niacin-induced flushing which is associated with a increased release of PGD2 from skin cells. It has been demonstrated that increased formation of PGD2 is associated with increased levels of urinary 11-dehydro-TxB2 in patients with mastocytosis.
In order to test whether niacin-induced biosynthesis of PGD2 is associated with formation of 11-dehydro-TxB2 the investigators will measure prostaglandin metabolites in blood and urine of volunteers receiving niacin. In addition, subjects will be treated with low or high dose aspirin prior to niacin to analyze the contribution of cyclooxygenase enzymes to biosynthesis of PGD2.
Arm 1: Subjects will receive 500 mg niacin. The subjects will collect urine (3-10 ml each) before niacin and every one-two hours after niacin for 10 h. Subjects will have blood drawn (2 teaspoons) before and at 0.5-1 h after niacin.
Arm 2: Subjects will take 81 mg aspirin (1 tablet of low-dose aspirin) daily for 7 days before niacin. Urine collection will be before and after aspirin, before niacin, and then in intervals as in arm 1. There will be a blood collection before niacin and 0.5-1 h after niacin.
Arm 3: Subjects will take 325 mg aspirin (1 tablet of regular strength aspirin) daily for 7 days before niacin. Urine collection will be before and after aspirin, before niacin, and then in intervals as in arm 1.
Arm 4: Subjects will be infused with 10 μg of deuterated PGD2 in a forearm vein over the course of 30 min. Subjects will collect a urine sample before and every two hours after deuterated PGD2 for 10 h.
- Conditions
- Metabolism of Prostaglandin D2
- Being tested
- niacin, aspirin, PGD2
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
niacinDietary supplement
induce biosynthesis of PGD2
aspirinDrug
inhibition of cyclooxygenase
PGD2Other
labeled precursor
| Study group | Role | What they receive |
|---|---|---|
| niacin | Experimental | Blood (10 ml) will be drawn from the subject. Immediately before or after the blood draw the subject will collect a urine (3-10 ml) sample. After the baseline blood draw and the urine sample is collected the subject will take 500 mg of niacin. The niacin will not be an extended release formulation. Subjects will be encouraged to drink plenty of water during the study. Subjects are instructed to collect urine 1, 2, 4, 6, 8, and 10 hours after niacin administration. Subjects will collect their urine in separate plastic tubes that will be provided to them.
Approximately 1-2 h after niacin administration a second blood sample (10 ml) will be drawn from the subject. Receives: Dietary Supplement: niacin |
| niacin + low-dose aspirin | Experimental | Volunteers will provide a urine sample. They will receive 7 tablets of low-dose aspirin (81 mg) and be instructed to take one tablet daily for 7 days. On the seventh day, they return to have blood drawn, urine collected, and receive niacin as described in arm 1. Receives: Dietary Supplement: niacin; Drug: aspirin |
| niacin + regular-strength aspirin | Experimental | Volunteers will provide a urine sample. They will receive 7 tablets of regular-strength aspirin (325 mg) and be instructed to take one tablet daily for 7 days. On the seventh day, they return to have blood drawn, urine collected, and receive niacin as described in arm 1. Receives: Dietary Supplement: niacin; Drug: aspirin |
| deuterated PGD2 | Experimental | Volunteers will come to the clinical research center. Volunteers will provide a urine sample. The volunteers will be fitted to record an electrocardiogram (ECG) and blood pressure. ECG will be recorded continuously. Blood pressure will be taken at baseline and every 10 minutes thereafter for one hour. The solution with deuterated PGD2 (10 microgram) will be infused over the course of 30 min. Volunteers will be monitored for 1 h after the end of the infusion, and volunteers will start collecting urine in intervals up to 10 h.
Infusion of the deuterated PGD2 solution will be performed in the presence of a physician. The injection solution will be prepared by Vanderbilt University Medical Center (VUMC) Investigational Drug Services. The solution will be sterile and pyrogen free. Receives: Other: PGD2 |
What is being measured
The primary outcome is the main question the study is designed to answer.
prostaglandin metabolites
metabolites will be quantified in urine and blood
Measured: 0-10 hours
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted9 Jul 2020
- Study start15 Aug 2020
- Primary completion30 Jul 2027 (estimated)
- Study completion31 Aug 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Metabolism of Prostaglandin D2Studies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Early Phase 1
- Primary purpose
- Basic science
- Allocation
- Non-randomised
- Intervention model
- Sequential
- Model description
- Participants may be participating in all 4 arms of the study or in less than 4 arms.
- Masking
- None (open label)
- Enrolment
- 10 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Vanderbilt University
- Sponsor type
- University, hospital or other
- Collaborators
- Vanderbilt University Medical Center
- Responsible party
- Principal investigator, Claus Schneider, Vanderbilt University
- Investigators
- Claus M Schneider, PhD, Principal investigator, Vanderbilt University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04464070
- Sponsor's protocol ID
- 150895
- Status last verified
- Jun 2026
- First submitted
- 1 Jul 2020
- Last updated
- 5 Jun 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- Yes: IPD (study protocol, informed consent forms) will be shared upon a justified request by an investigator.
Study at a glance
From the registry record, last updated by the sponsor on 5 Jun 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Novel Pathways of Eicosanoid Metabolism
- ClinicalTrials.gov ID
- NCT04464070
- Acronym / sponsor ID
- 150895
- Conditions
- Metabolism of Prostaglandin D2
- Phase
- Early Phase 1
- Study type
- Interventional
- Recruitment status
- Enrolling by invitation
- Enrolment
- 10 participants (estimated)
- Lead sponsor
- Vanderbilt UniversityUniversity, hospital or other
- Collaborators
- Vanderbilt University Medical Center
- Study start
- 15 Aug 2020 (actual)
- Primary completion
- 30 Jul 2027 (estimated)
- Study completion
- 31 Aug 2027 (estimated)
- First posted
- 9 Jul 2020 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Prostaglandins are important signaling compounds formed from arachidonic acid. The enzymes that form prostaglandins, cyclooxygenase-1 and -2 are the targets of non-steroidal anti-inflammatory drugs (NSAIDs). Because prostaglandins are very unstable in the body, they can not be measured directly. Instead, their metabolites are isolated from urine or blood and quantified as markers of formation of the parent, active compounds.
The investigators are testing the hypothesis that there is a previously unrecognized metabolic pathway between two prostaglandins. The investigators hypothesize that prostaglandin D2 (PGD2), in addition to its known metabolism to PGD-M, is also metabolized to 11-dehydro-thromboxane B2 (11-dehydro-TxB2).
Detailed description
The objective of this study is to determine whether PGD2 is metabolized to 11-dehydro-TxB2 in humans. Because the levels of PGD2 and its metabolite, PGD-M, are low in human urine, the investigators will use the model of niacin-induced flushing which is associated with a increased release of PGD2 from skin cells. It has been demonstrated that increased formation of PGD2 is associated with increased levels of urinary 11-dehydro-TxB2 in patients with mastocytosis.
In order to test whether niacin-induced biosynthesis of PGD2 is associated with formation of 11-dehydro-TxB2 the investigators will measure prostaglandin metabolites in blood and urine of volunteers receiving niacin. In addition, subjects will be treated with low or high dose aspirin prior to niacin to analyze the contribution of cyclooxygenase enzymes to biosynthesis of PGD2.
Arm 1: Subjects will receive 500 mg niacin. The subjects will collect urine (3-10 ml each) before niacin and every one-two hours after niacin for 10 h. Subjects will have blood drawn (2 teaspoons) before and at 0.5-1 h after niacin.
Arm 2: Subjects will take 81 mg aspirin (1 tablet of low-dose aspirin) daily for 7 days before niacin. Urine collection will be before and after aspirin, before niacin, and then in intervals as in arm 1. There will be a blood collection before niacin and 0.5-1 h after niacin.
Arm 3: Subjects will take 325 mg aspirin (1 tablet of regular strength aspirin) daily for 7 days before niacin. Urine collection will be before and after aspirin, before niacin, and then in intervals as in arm 1.
Arm 4: Subjects will be infused with 10 μg of deuterated PGD2 in a forearm vein over the course of 30 min. Subjects will collect a urine sample before and every two hours after deuterated PGD2 for 10 h.
Study design
- Primary purpose
- Basic science
- Allocation
- Non-randomised
- Intervention model
- Sequential
- Masking
- None (open label)
- Number of arms
- 4
- Model description
- Participants may be participating in all 4 arms of the study or in less than 4 arms.
| Arm | Type | Receives |
|---|---|---|
| niacin | Experimental | Dietary Supplement: niacinBlood (10 ml) will be drawn from the subject. Immediately before or after the blood draw the subject will collect a urine (3-10 ml) sample. After the baseline blood draw and the urine sample is collected the subject will take 500 mg of niacin. The niacin will not be an extended release formulation. Subjects will be encouraged to drink plenty of water during the study. Subjects are instructed to collect urine 1, 2, 4, 6, 8, and 10 hours after niacin administration. Subjects will collect their urine in separate plastic tubes that will be provided to them. Approximately 1-2 h after niacin administration a second blood sample (10 ml) will be drawn from the subject. |
| niacin + low-dose aspirin | Experimental | Dietary Supplement: niacin, Drug: aspirinVolunteers will provide a urine sample. They will receive 7 tablets of low-dose aspirin (81 mg) and be instructed to take one tablet daily for 7 days. On the seventh day, they return to have blood drawn, urine collected, and receive niacin as described in arm 1. |
| niacin + regular-strength aspirin | Experimental | Dietary Supplement: niacin, Drug: aspirinVolunteers will provide a urine sample. They will receive 7 tablets of regular-strength aspirin (325 mg) and be instructed to take one tablet daily for 7 days. On the seventh day, they return to have blood drawn, urine collected, and receive niacin as described in arm 1. |
| deuterated PGD2 | Experimental | Other: PGD2Volunteers will come to the clinical research center. Volunteers will provide a urine sample. The volunteers will be fitted to record an electrocardiogram (ECG) and blood pressure. ECG will be recorded continuously. Blood pressure will be taken at baseline and every 10 minutes thereafter for one hour. The solution with deuterated PGD2 (10 microgram) will be infused over the course of 30 min. Volunteers will be monitored for 1 h after the end of the infusion, and volunteers will start collecting urine in intervals up to 10 h. Infusion of the deuterated PGD2 solution will be performed in the presence of a physician. The injection solution will be prepared by Vanderbilt University Medical Center (VUMC) Investigational Drug Services. The solution will be sterile and pyrogen free. |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (1 listed)
- Normal, healthy volunteers not currently taking any medication.
Key exclusion criteria (1 listed)
- Use of anti-inflammatory/over-the-counter pain medications (NSAIDs) up to 2 weeks prior to study.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| niacininduce biosynthesis of PGD2 | Dietary supplement | niacin, niacin + low-dose aspirin, niacin + regular-strength aspirin |
| aspirininhibition of cyclooxygenase | Drug | niacin + low-dose aspirin, niacin + regular-strength aspirin |
| PGD2labeled precursor | Other | deuterated PGD2 |
Primary outcome
prostaglandin metabolites
Time frame: 0-10 hours
metabolites will be quantified in urine and blood
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 5 Jun 2026.
- Individual participant dataSharing planned: Yes. IPD (study protocol, informed consent forms) will be shared upon a justified request by an investigator.
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Claus M Schneider, PhD principal investigator
Vanderbilt University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Early Phase 1 study testing niacin, aspirin and PGD2 in people with Metabolism of Prostaglandin D2, run by Vanderbilt University at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 1 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: enrolling by invitation, as of the sponsor's last update on 5 Jun 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Early Phase 1 (sometimes called Phase 0) studies give a very small amount of a treatment to a few people, mainly to see how the body handles it.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
prostaglandin metabolites (time frame: 0-10 hours). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 5 Jun 2026.