Chronic Cough (CC)Phase 1NCT07085975
The Safety, Feasibility, and Repeatability of Inhaled ATP Cough Challenges
A Phase 1 study testing Adenosine 5'-triphosphate in people with Chronic Cough (CC) and Asthma, run by McMaster University at 1 site in Canada.
Trial summary
The inhalation of adenosine 5'-triphosphate (ATP) to evoke cough (ATP cough challenge) is becoming increasingly used as a tool to measure cough hypersensitivity in patients with chronic cough. However, the safety, feasibility, and repeatability of this procedure is not widely known. Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Chronic Cough (CC), Asthma
- What is being tested?
- Adenosine 5'-triphosphate
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 33 participants
- Where
- 1 siteCanada
- Study dates
- 5 Aug 2025to 1 Oct 2026
- Phase
- 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 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Eligible participants in Phase 1 will include healthy adults (≥18 years old) with:
- Normal spirometry; and
- No current or past medical history of chronic cough or other respiratory diseases.
- Eligible participants will include adults (≥18 years old) with:
- RCC/UCC for >1 year, demonstrated by a normal chest radiograph and no airflow obstruction (FEV1/FVC>0.7/LLN) with either:
- Insufficient improvement in cough despite treatment targeting any underlying condition(s) contributing to the cough (RCC); or
- Cough for which an underlying cause has not been determined despite thorough investigation (UCC).
- Mild steroid-naïve asthma who demonstrate evidence of a positive screening methacholine (PC20<16 mg/mL); symptoms of cough, shortness of breath, chest tightness, and wheeze, that, in the opinion of the qualified investigator, are well-controlled; and those have not used inhaled or oral corticosteroids for the past month.
Who cannot join
- We will exclude healthy individuals meeting the following:
- Are a current or former smoker with a >5 pack-year history and abstinence ≤6 months;
- Unable to perform acceptable and reproducible spirometry;
- Have unresolved symptoms of upper respiratory tract infection within 6 weeks prior to the first study visit;
- Have had a lower respiratory tract infection or pneumonia within 6 weeks prior to the first study visit;
- Presence of other primary pulmonary disorders, including pulmonary embolism, pulmonary hypertension, lung cancer, cystic fibrosis, radiologically-proven emphysema, severe bronchiectasis, or severe interstitial lung disease; or
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- History of psychiatric illness, drug, or alcohol abuse that could interfere with participation in the study.
- History of clinically-significant cardiovascular disease, including coronary artery disease, aortic aneurysm, or stroke in the last 3 months;
- Those with serious medical conditions or those who are not on stable medication(s) for their condition(s);
- Those with immune system disorders, severe allergy, or on allergy-specific immunotherapy;
- Any other condition, that, in the opinion of the qualified investigator, may adversely affect the participant's ability to complete the study or its measures or pose significant risk to the participant;
- Pregnant or breastfeeding;
- Women of child-bearing potential who:
- Do not agree to use a medically approved method of birth control for the duration of the study. All hormonal birth control must have been in use for a minimum of 3 months. Acceptable methods of birth control include oral contraceptives, hormone birth control patch, vaginal contraceptive ring, injectable contraceptives, or hormone implant, double-barrier method, intrauterine devices, non-heterosexual lifestyle or agrees to use contraception if planning on changing to heterosexual partner(s), vasectomy of partner at least 6 months prior to screening. Females who are not of child-bearing potential will be defined as females who have undergone a sterilization procedure (e.g., hysterectomy, bilateral oophorectomy, bilateral tubal ligation, complete endometrial ablation) or have been post-menopausal for at least 1 year prior to screening.
- Phase 2: Patients with RCC/UCC and mild-steroid naïve asthma
- Cohort-specific exclusion criteria include the following:
- For the RCC/UCC cohort:
- Current smoker or ex-smoker with ≥20 pack-year history and abstinence ≤6 months;
- For the mild steroid-naïve asthma cohort:
- Current smoker or ex-smoker with ≥20 pack-year history and abstinence ≤6 months;
- History or exacerbation or uncontrolled symptoms within the last month prior to the first study visit; and
- Use of inhaled or oral corticosteroids within the last month prior to the first study visit.
- We will exclude participants meeting any of the following criteria from the study:
- Unable to perform acceptable and reproducible spirometry;
- Unresolved symptoms of upper respiratory tract infection within 6 weeks prior to the first study visit;
- Lower respiratory tract infection or pneumonia within 6 weeks prior to the first study visit;
- Presence of other primary pulmonary disorders, including pulmonary embolism, pulmonary hypertension, lung cancer, cystic fibrosis, radiologically-proven emphysema, severe bronchiectasis, or severe interstitial lung disease;
- History of psychiatric illness, drug, or alcohol abuse that could interfere with participation in the study;
- History of clinically-significant cardiovascular disease, including coronary artery disease, aortic aneurysm, or stroke in the last 3 months;
- Those with serious medical conditions or those who are not on stable medication(s) for their condition(s);
- Those with immune system disorders, severe allergy, or on allergy-specific immunotherapy;
- Any other condition, that, in the opinion of the qualified investigator, may adversely affect the participant's ability to complete the study or its measures or pose significant risk to the participant;
- Pregnant or breastfeeding;
- Female participants of child-bearing potential who:
- Do not agree to use a medically approved method of birth control for the duration of the study;
- Have not been using hormonal birth control for a minimum of 3 months prior to screening.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Canada1 site, 1 recruiting
- Recruiting
Respiratory Research Lab
Hamilton, Ontario, L8N 3Z5
Imran Satia, MD PhD, 905-521-2100 ext. 76645, satiai@mcmaster.ca
About this study
The inhalation of adenosine 5'-triphosphate (ATP) to evoke cough (ATP cough challenge) is becoming increasingly used as a tool to measure cough hypersensitivity in patients with chronic cough. However, the safety, feasibility, and repeatability of this procedure is not widely known. In this study, we will perform ATP cough challenges in healthy individuals and in patients with mild asthma and chronic cough to better understand the safety, feasibility, and repeatability of these challenges. Such information will guide the future conduct of ATP cough challenges to measure cough hypersensitivity and identify patients who may better respond to ATP-blocking therapies.
- Conditions
- Chronic Cough (CC), Asthma
- Being tested
- Adenosine 5'-triphosphate
- Keywords
- adenosine triphosphate, chronic cough, asthma, cough hypersensitivity syndrome
- Medical subject headings
- Chronic Cough, Asthma, cough hypersensitivity syndrome
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Adenosine 5'-triphosphateDrug
Participants will inhale increasing doubling concentrations of adenosine 5'-triphosphate dissolved in 0.9% saline through the Aerogen Solo vibrating mesh nebulizer.
| Study group | Role | What they receive |
|---|---|---|
| Adenosine 5'triphosphate | Experimental | Not described Receives: Drug: Adenosine 5'-triphosphate |
What is being measured
The primary outcome is the main question the study is designed to answer.
The mean %FEV1 change from baseline at incremental doses of ATP
Measured: Until the end of the ATP cough challenge
Symptoms of wheeze measured on the mBorg scale at incremental doses of ATP
Measured: Until the end of the ATP cough challenge
Symptoms of chest tightness measured on the mBorg scale at incremental doses of ATP
Measured: Until the end of the ATP cough challenge
Symptoms of shortness of breath measured on the mBorg scale at incremental doses of ATP
Measured: Until the end of the ATP cough challenge
The mean change in oxygen saturations (SpO2) from baseline at incremental doses of ATP
Measured: Until the end of the ATP cough challenge
The intra-class correlation of measures obtained from repeat ATP cough challenges
Measured: Baseline to 1 week
The frequency of adverse events
Measured: Baseline to 1 week
Total maximum number of evoked coughs (Emax) by any dose of ATP
Measured: Until the end of the ATP cough challenge
The dose of ATP that induces at least 50% of the maximal cough response (ED50)
Measured: Until the end of the ATP cough challenge
The dose of ATP that induces at least 5 coughs (C5)
Measured: Until the end of the ATP cough challenge
The dose of ATP that induces at least 2 coughs (C2)
Measured: Until the end of the ATP cough challenge
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted25 Jul 2025
- Study start5 Aug 2025
- Primary completion1 Aug 2026 (estimated)
- Study completion1 Oct 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Chronic Cough (CC)Studies of the same condition, open and under way.
- More trials run by McMaster 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 1
- Primary purpose
- Diagnosis
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 33 participants (estimated)
Sponsor and investigators
- Lead sponsor
- McMaster University
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07085975
- Sponsor's protocol ID
- ATP-17839
- Status last verified
- Aug 2025
- First submitted
- 17 Jul 2025
- Last updated
- 29 Aug 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Study at a glance
From the registry record, last updated by the sponsor on 29 Aug 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Safety, Feasibility, and Repeatability of Inhaled ATP Cough Challenges
- ClinicalTrials.gov ID
- NCT07085975
- Acronym / sponsor ID
- ATP-17839
- Conditions
- Chronic Cough (CC), Asthma
- Keywords
- adenosine triphosphate, chronic cough, asthma, cough hypersensitivity syndrome
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 33 participants (estimated)
- Lead sponsor
- McMaster UniversityUniversity, hospital or other
- Study start
- 5 Aug 2025 (actual)
- Primary completion
- 1 Aug 2026 (estimated)
- Study completion
- 1 Oct 2026 (estimated)
- First posted
- 25 Jul 2025 (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 inhalation of adenosine 5'-triphosphate (ATP) to evoke cough (ATP cough challenge) is becoming increasingly used as a tool to measure cough hypersensitivity in patients with chronic cough. However, the safety, feasibility, and repeatability of this procedure is not widely known. In this study, we will perform ATP cough challenges in healthy individuals and in patients with mild asthma and chronic cough to better understand the safety, feasibility, and repeatability of these challenges. Such information will guide the future conduct of ATP cough challenges to measure cough hypersensitivity and identify patients who may better respond to ATP-blocking therapies.
Study design
- Primary purpose
- Diagnosis
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Adenosine 5'triphosphate | Experimental | Drug: Adenosine 5'-triphosphate |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (8 listed)
- Normal spirometry; and
- No current or past medical history of chronic cough or other respiratory diseases.
- RCC/UCC for >1 year, demonstrated by a normal chest radiograph and no airflow obstruction (FEV1/FVC>0.7/LLN) with either:
- Mild steroid-naïve asthma who demonstrate evidence of a positive screening methacholine (PC20<16 mg/mL); symptoms of cough, shortness of breath, chest tightness, and wheeze, that, in the opinion of the qualified investigator, are well-controlled; and those have not used inhaled or oral corticosteroids for the past month.
Key exclusion criteria (36 listed)
- Are a current or former smoker with a >5 pack-year history and abstinence ≤6 months;
- Unable to perform acceptable and reproducible spirometry;
- Have unresolved symptoms of upper respiratory tract infection within 6 weeks prior to the first study visit;
- Have had a lower respiratory tract infection or pneumonia within 6 weeks prior to the first study visit;
- Presence of other primary pulmonary disorders, including pulmonary embolism, pulmonary hypertension, lung cancer, cystic fibrosis, radiologically-proven emphysema, severe bronchiectasis, or severe interstitial lung disease; or
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 |
|---|---|---|
| Adenosine 5'-triphosphateParticipants will inhale increasing doubling concentrations of adenosine 5'-triphosphate dissolved in 0.9% saline through the Aerogen Solo vibrating mesh nebulizer. | Drug | Adenosine 5'triphosphate |
Primary outcome
The mean %FEV1 change from baseline at incremental doses of ATP
Time frame: Until the end of the ATP cough challenge
Symptoms of wheeze measured on the mBorg scale at incremental doses of ATP
Time frame: Until the end of the ATP cough challenge
Symptoms of chest tightness measured on the mBorg scale at incremental doses of ATP
Time frame: Until the end of the ATP cough challenge
Symptoms of shortness of breath measured on the mBorg scale at incremental doses of ATP
Time frame: Until the end of the ATP cough challenge
The mean change in oxygen saturations (SpO2) from baseline at incremental doses of ATP
Time frame: Until the end of the ATP cough challenge
The intra-class correlation of measures obtained from repeat ATP cough challenges
Time frame: Baseline to 1 week
The frequency of adverse events
Time frame: Baseline to 1 week
Total maximum number of evoked coughs (Emax) by any dose of ATP
Time frame: Until the end of the ATP cough challenge
The dose of ATP that induces at least 50% of the maximal cough response (ED50)
Time frame: Until the end of the ATP cough challenge
The dose of ATP that induces at least 5 coughs (C5)
Time frame: Until the end of the ATP cough challenge
The dose of ATP that induces at least 2 coughs (C2)
Time frame: Until the end of the ATP cough challenge
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 29 Aug 2025.
- Individual participant dataSharing planned: Undecided
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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.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing Adenosine 5'-triphosphate in people with Chronic Cough (CC) and Asthma, run by McMaster University at 1 site in Canada.
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 36 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 29 Aug 2025. 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 Canada. 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?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
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 Imran Satia, MD PhD (905-525-2100 ext. 76228, satiai@mcmaster.ca), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
The mean %FEV1 change from baseline at incremental doses of ATP (time frame: Until the end of the ATP cough challenge). The study lists 11 primary outcomes in all. 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 29 Aug 2025.