NCT03926741CompletedEarly phase 1

GSNOR Phenotyping/GSNO Challenge in Severe Asthma

Methods to Identify and Treat Severe Asthma Patients Project 1: GSNOR Phenotyping and GSNO Challenge

Source: ClinicalTrials.gov · Last updated 20 May 2026

Brief summary (registry, in English)

Asthma is caused by or worsened by different things in different people. It is because of these differences that not all people with asthma respond the same to all treatments and medicines. If the investigators can better identify the changes in the airways or breathing pipes in patients with asthma, the investigators may be able to help patients make better choices about the medicines or treatments that are most likely to work best for each patient. This research study is about one specific factor that is known to affect asthma in some patients. It involves an increase in the activity of an enzyme that is in people's airways. An enzyme is something that helps a chemical reaction to occur. The enzyme the investigators are studying in this research study is called GSNOR (S-nitrosoglutathione reductase) , and when the activity of this enzyme is increased, the result is that there is less GSNO (S-nitrosoglutathione) . GSNO is a chemical that protects people's airways. The initials stand for S-nitrosoglutathione, (pronounced s-nahy-troh-soh-gloo-tuh-thahy-ohn), and it is naturally produced by the body. It has an important role in regulating respiratory function (breathing) and preventing inflammation (swelling) in the respiratory tract (throat, airways, and lungs). The amount of GSNO found in the body is controlled by the enzyme GSNOR (S-nitrosoglutathione reductase). GSNOR breaks down GSNO. Too much GSNOR leads to low levels of GSNO, and that can cause inflammation (swelling) and loss of airway function in some asthma patients. The only way to measure GSNOR levels currently is with a bronchoscopy procedure where a scope is inserted into the patient's airways, often under sedation. This research study is being done to test the accuracy of another type of test that can be done in the doctor's office, rather than in a procedure area. This non-invasive diagnostic test, called a GSNO Challenge test, may be able to identify which asthma patients have increased activity of the airway enzyme GSNOR. The investigators are also studying the phenotypes (observable traits) in asthma patients with increased levels of GSNOR. If this research study is successful, in the future (after this research study is done). The investigators may be able to offer a cost-effective and non-invasive way to identify patients who have higher GSNOR activity levels and offer personalized treatments. The GSNO Challenge test includes giving an investigational drug to breathe in (inhale). The investigational drug is GSNO. "Investigational" means the drug is not approved by any regulatory agencies including the Food and Drug Administration (FDA), and is still being tested for safety and effectiveness. The research is registered with the FDA, but again the GSNO treatment in this study (administered during the GSNO challenge testing) is not an approved treatment or diagnostic test for asthma.

Status (registry): Completed
Phase (registry): Early phase 1
Study type: Interventional
Enrollment: 48 (actual)
First submitted: 19 Mar 2019
Start date: 30 Apr 2019
Primary completion date: 29 Feb 2024
Lead sponsor: James Reynolds
Diseases: Asthma
NCT number: NCT03926741

What you commit to

Study type: Interventional · Early phase 1
Participants enrolled: 48
From 30 Apr 2019 to the primary completion date, 29 Feb 2024
2 sites in 1 country
Visits and tests: ask the trial team, the registry does not list them

Built from the registry fields of ClinicalTrials.gov. It describes the study, not your situation.

Who cannot take part

Copied verbatim from ClinicalTrials.gov and grouped by topic. Only the trial team decides who can take part.

Prior treatment

Individuals with prior diagnosis of vocal cord dysfunction or an anatomic anomaly that would increase the risks associated with the bronchoscopy procedure
Prior diagnosis of cystic fibrosis, COPD, or other additional lung disease that in the investigator's opinion would make participant unsuitable for study participation
Asthma exacerbation requiring oral corticosteroids within the previous 30 days (can be rescreened)
Respiratory or other infection requiring systemic antibiotics within the previous 14 days (can be rescreened)
Unable or unwilling to withhold medications prior to certain study procedures (skin test, spirometry, methacholine challenge)
Participation in any investigational drug study other than the Airway pH Study within the 4 week period prior to screening.

Other illness

History of premature birth before 35 weeks gestation
Allergic to anesthetic medication(s) that would prevent participation in the study's bronchoscopy
Individuals with diabetes mellitus (type 1 or type 2)
Individuals who report additional chronic diseases requiring medication of the heart, lungs, kidney, liver, brain, etc., or afflicted with any acute or chronic pathology that in the opinion of the screening physician makes them unsuitable for study such as coronary artery disease
Inherited or acquired blood coagulation disorder, congenital methemoglobinemia, or a familial hemoglobinopathy that impacts oxygen delivery (e.g., sickle cell)
Any illness, condition or recent surgeries that may increase the risks associated with the study
Any acute viral illness, including active COVID-19 infection or acute viral respiratory symptoms; can rescreen 4 weeks after positive test result.

Lab values

Individuals with renal failure or creatinine \> 1.8 mg/dl at time of screening

Other

-\> 5 pack year smoking history
Body mass index (BMI) \> 45
Unable to perform repeatable consistent efforts in pulmonary function testing
Planning to relocate away from the clinical center (Cleveland, Ohio or central Indiana) area before study completion
Lack of reliable communications channel (hard-wire phone, cell phone, email for follow-up contacts after bronchoscopy)
Blood pressure parameters outside the normal range of 90-180 mm Hg systolic and 50-100 mm Hg diastolic at time of screening
Individuals who are pregnant, breastfeeding, or are unwilling to use a medically acceptable method of birth control (as indicated on the Birth Control Methods Reference Card) from the time of consent until the end of the study to avoid pregnancy
More than 3 exacerbations within the past 6 months
Intubated for asthma within the past 12 months
Current use of a vitamin K antagonist (warfarin) or other anticoagulant (e.g., heparin, clopidogrel, enoxaparin or dalteparin)
Current use of beta-adrenergic blockers, tricyclic antidepressants, meperidine (or related central nervous system (CNS) agents), or nitrates

Who the study is looking for

For subjects with Asthma
Adult males or females age ≥ 18 and ≤ 50 years at the time of enrollment
Non-smoker
Physician diagnosis of asthma for at least one year
FEV1 bronchodilator reversibility \> 12% or methacholine PC20 \< 16 mg/ml (historical methacholine data from previous NIH trials including SARP and AsthmaNet will be allowed)
Baseline post maximal bronchodilator FEV1 \>55% predicted
- Healthy Volunteers
Adult males or females age ≥ 18 and ≤ 50 years at time of enrollment
Non-smoker
No history of asthma, chronic obstructive pulmonary disease (COPD), or other chronic lung disease
No history of severe allergic/atopic disease requiring immunotherapy or immunomodulators

Age in the registry: 18 years to 50 years · Sex: All · Accepts healthy volunteers

Full criteria on ClinicalTrials.gov

Sites (2)

Sites in registry order. Pick your city on the disease page to sort them by distance.

Site	City	Country	Site status
University Hospitals Cleveland Medical Center* Coordinator of this site? Confirm its status	Cleveland	United States	Unknown status
Indiana University School of Medicine Coordinator of this site? Confirm its status	Indianapolis	United States	Unknown status

This page is information, not medical advice. Discuss any trial with your doctor.