Mild or Moderate Asthma With Allergic SensitizationPhase 2NCT04160910
5HTP Regulation Of Asthma In Children
A Phase 2 study testing 5-Hydroxytryptophan in people with Mild or Moderate Asthma With Allergic Sensitization, run by Indiana University at 1 site in United States.
Trial summary
The purpose of this study is to learn more about if taking a supplement called 5-hydroxytryptophan (5HTP) can improve breathing and anxiety symptoms related to asthma. To help learn more subjects will either be assigned to a group that is taking the supplement (5HTP) or a group that is taking a placebo. Read more about this study
- Who is it for?
- Ages 8 to 18 years
- Conditions the study is for
- Mild or Moderate Asthma With Allergic Sensitization
- What is being tested?
- 5-Hydroxytryptophan
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 20 participants
- Where
- 1 siteUnited States
- Study dates
- 11 Feb 2021to 31 Dec 2026
- Phase
- Phase 2
- 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 8 to 18 years
- All sexes
- No healthy volunteers
- Child, Adult
Who may be able to join
- Age 8-18 Years of Age
- Mild to Moderate Asthma based on ATS guidelines
- Positive Allergy Test (positive skin or serum IgE)
- Weight ≥ 70 lbs (32 kg)
- CES-DC cut-off ≥ 15 (total score range is 0 to 60) or SCARED cut-off
- 25 (total score range is 0 to 142)
- Ability to comply with study visits and study procedures
- Informed Consent by participant and if applicable the parent or legal guardian
Who cannot join
- Currently taking a SSRI
- Taking a leukotriene inhibitor (montelukast, Zileuton)
- Severe Asthma Based on ATS Guidelines
- Taking a biologic medication (omalizumab, mepolizumab, benralizumab, dupilumab)
- Medical History of Adverse Reaction to 5HTP
- Physical findings that would compromise the safety of the study or the quality of the study data
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
Indiana University
Indianapolis, Indiana, 46202
Lisa Bendy, MBA, 317-278-7152, lbendy@iu.edu
Lisa Bendy, MBA, 3172787152, lbendy@iu.edu
About this study
The purpose of this study is to learn more about if taking a supplement called 5-hydroxytryptophan (5HTP) can improve breathing and anxiety symptoms related to asthma. To help learn more subjects will either be assigned to a group that is taking the supplement (5HTP) or a group that is taking a placebo. This will be decided randomly. Later in the study subjects will crossover to the other group.There are 5 study visits over the course of about 12 weeks.
Read the detailed description
The objective of this study is to test the hypothesis that over-the-counter amino acid supplement 5HTP (isolated from the plant Griffonia Simplifolia) reduces human allergic lung responses and consequently improves lung function. The primary outcome is the change in FEV1. We anticipate the 5HTP at the proposed doses will improve lung function as in preclinical studies that used clinically relevant 5HTP. Secondary outcomes will be blood eosinophil counts and reduced symptoms for anxiety/depression, as seen in changes in the anxiety-depression scores from questionnaires (CES-DC \& SCARED). The results from these studies have the transformative potential to influence approaches to improve lung function and asthma-associated anxiety/depression.
- Aim 1: Test that 5HTP improves lung function in children with allergic asthma
- Aim 2: Test that 5HTP reduces eosinophil numbers in the blood and nasal fluid of patients with asthma from Aim 1
- Aim 3: Test that 5HTP decreases lung inflammation, increases cortisol and prolactin without altering systemic plasma concentrations of 5HTP, serotonin, 5-hydroxyindoleacetic acid (5-HIAA), and dopamine
- Being tested
- 5-Hydroxytryptophan, Placebo
- Medical subject headings
- Lymphoma, Follicular
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
5-HydroxytryptophanDrug
Also called 5HTP
Double blinded placebo controlled. 28 day dosing period followed by 3 week washout period. Then crossover to other arm of study
PlaceboDrug
Double blinded placebo controlled. 28 day dosing period followed by 3 week washout period. Then crossover to other arm of study
| Study group | Role | What they receive |
|---|---|---|
| 5-hydroxytryptophan | Active comparator | Dosage of 5-hydroxytryptophan will be determined by weight:
If subject weighs less than 100lbs: 50mg twice a day If subject weights more than 100lbs: 100mg twice a day Receives: Drug: 5-Hydroxytryptophan |
| Placebo | Placebo comparator | Dosage of placebo will be determined by weight:
If subject weighs less than 100lbs: 50mg twice a day If subject weights more than 100lbs: 100mg twice a day Receives: Drug: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Pulmonary Function Testing will be performed to assess for a change in Forced Expiratory Volume at one second (FEV1)
Pulmonary function testing will be performed at Baseline, Day 28, and Day 49, and Day 77
Measured: 77 days
Secondary outcomes (2)
Blood will be obtained to assess Eosinophil Count
Will be performed at Baseline, Day 28, and Day 49, and Day 77
Measured: 77 days
Questionnaires will be utilized to look for a decrease in symptoms for Anxiety/Depression Reduced Symptoms for Anxiety/Depression
Changes in Anxiety/Depression will be determined via questionnaire that will be administered at Baseline, Day 28, and Day 49, and Day 77 . Will use the Center for Epidemiological Studies Depression Scale for Children (CES-DC) to measure depression and Screen for Child Anxiety Related Disorders (SCARED)
Measured: 77 days
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted13 Nov 2019
- Study start11 Feb 2021
- Primary completion31 Dec 2026 (estimated)
- Study completion31 Dec 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Mild or Moderate Asthma With Allergic SensitizationStudies of the same condition, open and under way.
- More trials run by Indiana UniversityThe sponsor's other registered studies.
- 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
- Phase 2
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Triple blind
- Who is masked
- Participant, Care provider, Investigator
- Enrolment
- 20 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Indiana University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Kirsten Kloepfer, Indiana University
- Investigators
- Kirsten Kloepfer, MD, Principal investigator, Indiana University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04160910
- Sponsor's protocol ID
- Kloepfer_1902366300
- Status last verified
- Sep 2026
- First submitted
- 24 Oct 2019
- Last updated
- 1 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 1 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- 5HTP Regulation Of Asthma In Children
- ClinicalTrials.gov ID
- NCT04160910
- Acronym / sponsor ID
- Kloepfer_1902366300
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 20 participants (estimated)
- Lead sponsor
- Indiana UniversityUniversity, hospital or other
- Study start
- 11 Feb 2021 (actual)
- Primary completion
- 31 Dec 2026 (estimated)
- Study completion
- 31 Dec 2026 (estimated)
- First posted
- 13 Nov 2019 (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.
The purpose of this study is to learn more about if taking a supplement called 5-hydroxytryptophan (5HTP) can improve breathing and anxiety symptoms related to asthma. To help learn more subjects will either be assigned to a group that is taking the supplement (5HTP) or a group that is taking a placebo. This will be decided randomly. Later in the study subjects will crossover to the other group.There are 5 study visits over the course of about 12 weeks.
Detailed description
The objective of this study is to test the hypothesis that over-the-counter amino acid supplement 5HTP (isolated from the plant Griffonia Simplifolia) reduces human allergic lung responses and consequently improves lung function. The primary outcome is the change in FEV1. We anticipate the 5HTP at the proposed doses will improve lung function as in preclinical studies that used clinically relevant 5HTP. Secondary outcomes will be blood eosinophil counts and reduced symptoms for anxiety/depression, as seen in changes in the anxiety-depression scores from questionnaires (CES-DC \& SCARED). The results from these studies have the transformative potential to influence approaches to improve lung function and asthma-associated anxiety/depression.
- Aim 1: Test that 5HTP improves lung function in children with allergic asthma
- Aim 2: Test that 5HTP reduces eosinophil numbers in the blood and nasal fluid of patients with asthma from Aim 1
- Aim 3: Test that 5HTP decreases lung inflammation, increases cortisol and prolactin without altering systemic plasma concentrations of 5HTP, serotonin, 5-hydroxyindoleacetic acid (5-HIAA), and dopamine
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Triple blind (participant, care provider, investigator)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| 5-hydroxytryptophan | Active comparator | Drug: 5-HydroxytryptophanDosage of 5-hydroxytryptophan will be determined by weight: If subject weighs less than 100lbs: 50mg twice a day If subject weights more than 100lbs: 100mg twice a day |
| Placebo | Placebo comparator | Drug: PlaceboDosage of placebo will be determined by weight: If subject weighs less than 100lbs: 50mg twice a day If subject weights more than 100lbs: 100mg twice a day |
Who may qualify
- Ages
- 8 to 18 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult
Key inclusion criteria (8 listed)
- Age 8-18 Years of Age
- Mild to Moderate Asthma based on ATS guidelines
- Positive Allergy Test (positive skin or serum IgE)
- Weight ≥ 70 lbs (32 kg)
- CES-DC cut-off ≥ 15 (total score range is 0 to 60) or SCARED cut-off
Key exclusion criteria (6 listed)
- Currently taking a SSRI
- Taking a leukotriene inhibitor (montelukast, Zileuton)
- Severe Asthma Based on ATS Guidelines
- Taking a biologic medication (omalizumab, mepolizumab, benralizumab, dupilumab)
- Medical History of Adverse Reaction to 5HTP
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 |
|---|---|---|
| 5-HydroxytryptophanAlso: 5HTPDouble blinded placebo controlled. 28 day dosing period followed by 3 week washout period. Then crossover to other arm of study | Drug | 5-hydroxytryptophan |
| PlaceboDouble blinded placebo controlled. 28 day dosing period followed by 3 week washout period. Then crossover to other arm of study | Drug | Placebo |
Primary outcome
Pulmonary Function Testing will be performed to assess for a change in Forced Expiratory Volume at one second (FEV1)
Time frame: 77 days
Pulmonary function testing will be performed at Baseline, Day 28, and Day 49, and Day 77
2 secondary outcomes
Blood will be obtained to assess Eosinophil Count
Time frame: 77 days
Questionnaires will be utilized to look for a decrease in symptoms for Anxiety/Depression Reduced Symptoms for Anxiety/Depression
Time frame: 77 days
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 1 Oct 2026.
- Individual participant dataSharing planned: No
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.
Kirsten Kloepfer, MD principal investigator
Indiana University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing 5-Hydroxytryptophan in people with Mild or Moderate Asthma With Allergic Sensitization, run by Indiana 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 8 inclusion and 6 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: looking for participants now, as of the sponsor's last update on 1 Oct 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. Some participants in this study may receive a placebo. 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?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
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?
Contact Kirsten Kloepfer, MD ((317) 278-7860, kloepfer@iu.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Pulmonary Function Testing will be performed to assess for a change in Forced Expiratory Volume at one second (FEV1) (time frame: 77 days). 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 1 Oct 2026.