Allergen Inhalation Challenge for Asthma

(MATT Trial)

Not yet recruiting at 1 trial location

Overseen By Paul Obyrne, MB

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: McMaster University

Must not be taking: Asthma medications

Disqualifiers: Respiratory infection, Lung disease, Smoking, others

Compensation: Varies

Number of Visits: 6

Duration: 6 days (3 days per triad with a 4-week washout between allergen and diluent challenges)

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial aims to understand how mild allergic asthma affects lung function by testing lung responses to inhaled allergens (allergen challenge) and saline (a harmless saltwater solution, saline challenge). By comparing reactions to both, researchers hope to learn more about asthma and its impact on breathing. This trial suits individuals with mild allergic asthma who have experienced asthma responses to allergens and do not smoke. Participants must manage their asthma with short-acting inhalers and avoid rigorous exercise before visits. As an unphased trial, this study offers participants the opportunity to contribute to foundational asthma research and enhance understanding of asthma management.

Will I have to stop taking my current medications?

You may need to stop taking some asthma medications, as the trial only allows the use of short-acting β2-agonists for asthma treatment. It's best to discuss your current medications with the study team to see if they are allowed.

Is there any evidence suggesting that this trial's treatments are likely to be safe?

Research has shown that inhaling allergens is usually safe for individuals with mild allergic asthma, though it can occasionally worsen asthma symptoms. Studies have found that allergens can cause lung airways to swell and become irritated, making breathing more difficult. However, these reactions are generally manageable and expected in a clinical trial setting. Medical professionals closely monitor participants to ensure their safety. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about the Allergen Inhalation Challenge for asthma because it offers a unique way to understand how asthma reacts to specific allergens. Unlike standard treatments like inhaled corticosteroids or bronchodilators, which manage symptoms, this method directly involves the controlled exposure to allergens, helping to identify specific triggers and the body's response. By using an inhaled allergen and comparing it with a saline placebo, researchers aim to gain insights into the mechanisms of asthma, paving the way for more targeted and personalized treatment options in the future.

What evidence suggests that this trial's treatments could be effective for asthma?

This trial will compare the effects of an allergen challenge with a saline challenge. Research has shown that allergen challenges help researchers understand allergic asthma by safely triggering asthma-like symptoms. In past studies, inhaling allergens caused early and late asthma responses, such as difficulty breathing, in many participants. These reactions enable researchers to evaluate the effectiveness of asthma treatments. The allergen challenge also induces airway inflammation, a main feature of asthma. This method tests the effectiveness of different asthma medications by observing changes in airway reactions. ^{4 5 6 7 8}

Who Is on the Research Team?

Gail Gauvreau, PhD

Principal Investigator

McMaster University

Are You a Good Fit for This Trial?

This trial is for adults aged 18-75 with mild atopic asthma, who can perform required procedures and likely to follow the study plan. They must have a positive skin test for allergens, not exercise before visits, avoid certain asthma medications, and be non-smokers or long-term ex-smokers without significant past smoking history.

Inclusion Criteria

Methacholine provocative concentration causing a 20% fall in forced expiratory volume in 1 second of ≤ 16 mg/ml during the first methacholine inhalation challenge

Forced expiratory volume after 1 second greater than 70% predicted at the first screening visit

Demonstrated (or historic documentation of) early asthmatic response following the allergen inhalation challenge

Exclusion Criteria

Known to have tested positive for human immunodeficiency virus or hepatitis

Reported use of illegal drugs or history of abuse of prescription drugs or alcohol within 1 year before the first screening visit

Inability to produce a sputum sample at the first study visit

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants undergo inhaled allergen and diluent challenges over two triads, each consisting of 3 consecutive days

6 days (3 days per triad with a 4-week washout between allergen and diluent challenges)

6 visits (in-person)

Washout

A four-week washout period between allergen and diluent inhalation challenges

4 weeks

Follow-up

Participants are monitored for safety and effectiveness after treatment

4 weeks

What Are the Treatments Tested in This Trial?

Interventions

• Allergen challenge
• Saline challenge

Trial Overview

The study tests lung function after inhaling either an allergen or saline (a control substance). It involves measuring changes in breathing and analyzing biological samples to understand inflammation caused by allergens in people with mild allergic asthma.

How Is the Trial Designed?

Group I: Allergen Challenge Experimental Treatment 1 Intervention

Inhaled allergen

Group II: Diluent Challenge Placebo Group 1 Intervention

Inhaled saline

Who Is Running the Clinical Trial?

McMaster University

Lead Sponsor

Trials

936

Recruited

2,630,000+

Citations

1.

pmc.ncbi.nlm.nih.gov

pmc.ncbi.nlm.nih.gov/articles/PMC2677787/

Understanding allergic asthma from allergen inhalation tests

The allergen challenge model was used, particularly in the Netherlands (20–23) and in the United Kingdom (24–27), to document effectiveness of asthma drugs.

2.

pmc.ncbi.nlm.nih.gov

pmc.ncbi.nlm.nih.gov/articles/PMC4345962/

High- and low-dose allergen challenges in asthmatic patients ...

Results. The high-dose allergen challenge caused an early and late asthmatic response in 19 of 28 patients; the mean maximal fall in the forced expiratory ...

3.

onlinelibrary.wiley.com

onlinelibrary.wiley.com/doi/10.1111/all.15817

Standardization of clinical outcomes used in allergen ...

Allergen challenge (AC) is a valuable tool which is capable of inducing airway inflammation by triggering the T2-pathway resulting in the ...

4.

nejm.org

nejm.org/doi/full/10.1056/NEJMoa1411776

Allergen-Induced Asthmatic Responses Modified by a ...

Treatment with SB010 significantly attenuated both late and early asthmatic responses after allergen provocation in patients with allergic asthma.

5.

jacionline.org

jacionline.org/article/S0091-6749(13)01337-7/fulltext

Inhaled allergen bronchoprovocation tests

The repeated low-dose allergen challenge primarily allows evaluation of allergen-induced changes in AHR and airway inflammation. The increases in AHR can be ...

6.

pmc.ncbi.nlm.nih.gov

pmc.ncbi.nlm.nih.gov/articles/PMC9403392/

Allergen provocation tests in respiratory research

Inhalation of a provocative allergen in subjects with mild allergic asthma, while generally safe and well tolerated, can lead to significant ...

7.

pmc.ncbi.nlm.nih.gov

pmc.ncbi.nlm.nih.gov/articles/PMC4878003/

Allergen inhalation challenge, refractoriness and the ...

Studies that employ repeat allergen exposure (e.g. low dose allergen challenge methodology) have shown worsened asthma outcomes, including ...

8.

sciencedirect.com

sciencedirect.com/science/article/abs/pii/S0091674913013377

Inhaled allergen bronchoprovocation tests

In proof-of-efficacy studies thus far, allergen challenge showed a fair positive predicted value and an excellent negative predictive value for the actual ...