The Safety, Feasibility, and Repeatability of Inhaled ATP Cough Challenges

NCT07085975 | Recruiting Phase 1

• 1 other identifier: ATP-17839
• Study Type: interventional
• Target: 33
• Locations: 1 country
• Sites: 1

Brief 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. 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

Keywords

adenosine triphosphate; chronic cough; asthma; cough hypersensitivity syndrome

Outcome Measures

Primary Outcomes (11)

• The mean %FEV1 change from baseline at incremental doses of ATP

  Until the end of the ATP cough challenge

• Symptoms of wheeze measured on the mBorg scale at incremental doses of ATP

  Until the end of the ATP cough challenge

• Symptoms of chest tightness measured on the mBorg scale at incremental doses of ATP

  Until the end of the ATP cough challenge

• Symptoms of shortness of breath measured on the mBorg scale at incremental doses of ATP

  Until the end of the ATP cough challenge

• The mean change in oxygen saturations (SpO2) from baseline at incremental doses of ATP

  Until the end of the ATP cough challenge

• The intra-class correlation of measures obtained from repeat ATP cough challenges

  Baseline to 1 week

• The frequency of adverse events

  Baseline to 1 week

• Total maximum number of evoked coughs (Emax) by any dose of ATP

  Until the end of the ATP cough challenge

• The dose of ATP that induces at least 50% of the maximal cough response (ED50)

  Until the end of the ATP cough challenge

• The dose of ATP that induces at least 5 coughs (C5)

  Until the end of the ATP cough challenge

• The dose of ATP that induces at least 2 coughs (C2)

  Until the end of the ATP cough challenge

Study Arms (1)

Adenosine 5'triphosphate

EXPERIMENTAL

Drug: Adenosine 5'-triphosphate

Interventions

Adenosine 5'-triphosphate DRUG

Participants will inhale increasing doubling concentrations of adenosine 5'-triphosphate dissolved in 0.9% saline through the Aerogen Solo vibrating mesh nebulizer.

Adenosine 5'triphosphate

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• 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.

You may not qualify if:

• We will exclude healthy individuals meeting the following:
• (1) 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
• 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

Sponsors & Collaborators

• McMaster University: lead

Study Sites (1)

Respiratory Research Lab

Hamilton, Ontario, L8N 3Z5, Canada

RECRUITING

MeSH Terms

Conditions

Chronic Cough; Asthma; cough hypersensitivity syndrome

Interventions

Adenosine Triphosphate

Condition Hierarchy (Ancestors)

Cough; Respiration Disorders; Respiratory Tract Diseases; Signs and Symptoms, Respiratory; Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Bronchial Diseases; Lung Diseases, Obstructive; Lung Diseases; Respiratory Hypersensitivity; Hypersensitivity, Immediate; Hypersensitivity; Immune System Diseases

Intervention Hierarchy (Ancestors)

Adenine Nucleotides; Purine Nucleotides; Purines; Heterocyclic Compounds, 2-Ring; Heterocyclic Compounds, Fused-Ring; Heterocyclic Compounds; Nucleotides; Nucleic Acids, Nucleotides, and Nucleosides; Ribonucleotides

Central Study Contacts

Imran Satia, MD PhD

CONTACT

905-525-2100; satiai@mcmaster.ca

Study Design

• Study Type: interventional
• Phase: phase 1
• Allocation: NA
• Masking: NONE
• Purpose: DIAGNOSTIC
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: July 17, 2025
• First Posted: July 25, 2025
• Study Start: August 5, 2025
• Primary Completion (Estimated): August 1, 2026
• Study Completion (Estimated): October 1, 2026
• Last Updated: August 29, 2025

Record last verified: 2025-08

Locations

CA (1)