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Completed

NCT Number: NCT04678063

Validation of Strasbourg Environmental Exposure Chamber ALYATEC in Cat Allergic Subjects With Asthma

This is a randomized, double blind, cross-over study designed to determine the concentration of airborne cat allergen inducing bronchial response in asthmatic subjects allergic to cat, during allergen exposures in the Alyatec environmental exposure chamber (EEC).

The study was also designed to validate the specificity of the asthmatic reaction induced by exposure to airborne cat allergen in Alyatec EEC.

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Key information

Conditions

Allergic Asthma Allergy Allergy to Cats Hypersensitivity Hypersensitivity, Immediate Immune System Diseases Nose Diseases Otorhinolaryngologic Diseases Respiratory Hypersensitivity Respiratory Tract Diseases Rhinitis Rhinitis, Allergic

Age range

18 year–65 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Alyatec

Strasbourg, Grand Est, 67000, France

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Subjects having signed the informed consent
  • Subjects affiliated to a social security scheme
  • Non-specific bronchial hyperreactivity (HRBNS) assessed by a positive methacholine test
  • FEV1 value > 70% of theoretical FEV1 value
  • Asthma Control Test (ACT) ≥ 20/25 in 4 weeks prior to EEC exposure
  • Women of childbearing potential should have a negative pregnancy test throughout the study period with effective contraception.

Group A:

  • Cat allergic asthma (GINA 1, 2) associated with rhinitis and / or conjunctivitis symptoms triggered during an exposure to a cat.
  • Positive skin prick-test to cat allergen extract (wheal diameter >3 mm compared to the negative control) Specific immunoglobulin E (IgE) for cat allergen > 0.7 kU/L

Group B:

  • Mild allergic asthma (GINA 1 or 2) not sensitized to cat allergen with associated rhinitis and/or conjunctivitis.
  • Negative skin prick-test and specific IgE for cat allergen
  • Positive skin prick-test and specific IgE for another allergen.

Exclusion criteria

  • Uncontrolled asthma, ACT asthma control questionnaire less than 20, in the last 4 weeks
  • Uncontrolled asthma 2 weeks after interruption of LABA
  • Long-term treatment by LABA, within 2 weeks prior to inclusion
  • Existence of a severe obstructive syndrome with FEV1 <70% of the theoretical value
  • Obstruction triggered by spirometric evaluations
  • Hospitalization for asthma or exacerbation in the last 4 weeks
  • Subjects treated with oral corticosteroids in the 4 weeks prior to inclusion in the study
  • History of severe acute asthma requiring hospitalization in intensive care or intubation
  • Subjects treated with biotherapy in the 4 months prior to inclusion in the study
  • Presence of a cat at home, or daily exposure to cat allergens
  • Desensitization to cat allergens in the last 6 months
  • Active tobacco: plus 10 cigarettes / day or tobacco history plus 10 PA

Treatment and study plan

Exposure to Placebo

Other

Patients are exposed to placebo in the EEC

Exposure to dose A and dose B of cat allergen

Other

Patients are exposed to dose A and B for successive exposures in the EEC

Exposure to a single dose of cat allergen

Other

Patients are exposed to a single dose of cat allergen in the EEC according to the dose selected to achieve the main objective (dose A or B)

Primary outcomes

  1. Determine the concentration of cat allergen (in ng/m3 of Der p1) necessary to induce a bronchial response in at least 60% of asthmatic subjects allergic to cat.

    Time frame: 10 hours: 4 hours of exposure in EEC then 6 hours post-exposure

    The bronchial response is evaluated by measuring FEV1 value.

    Early asthmatic response (EAR) occurs when a 20 percent drop in FEV1 is detected during the exposure compared to the pre-exposure FEV1.

    Late bronchial response (LAR) occurs when a 15 percent drop in FEV1 or 20 percent drop in peak flow is detected 1 to 6h after the EAR.

Secondary outcomes

  1. Evaluate the safety of allergenic exposure in EEC

    Time frame: 28 hours: 4 hours of exposure in EEC then 24 hours post-exposure

    Safety is assessed with an asthma symptom self-report questionnaire performed during the 4h exposure and for 24h after the end of the exposure.

    The score was obtained from the sum of all four individual symptom scores (chest tightness, cough, wheezing and dyspnea) with a total possible score ranging from 0 (no symptoms) to 16 (maximum symptom intensity).

  2. Evaluate the allergen concentration in the EEC

    Time frame: 4 hours exposure in EEC

    The measurement of allergen concentration is performed with several sensors positioned in the chamber.

  3. Evaluate the specificity of the bronchial response

    Time frame: 4 hours exposure in EEC

    The specificity of the bronchial response is assessed with the exposure to cat allergen in the EEC of asthmatic allergic subjects non sensitized to cat.

  4. Evaluate the effect of the exposure on rhinitis symptoms

    Time frame: 28 hours: 4 hours of exposure in EEC then 24 hours post-exposure

    The effect of the exposure on the rhinitis response is assessed with Total Nasal Symptom Score (TNSS).

    The TNSS was obtained from the sum of all four individual symptom scores, with a total possible score ranging from 0 (no symptoms) to 12 (maximum symptom intensity).

  5. Evaluate the effect of the exposure on conjunctivitis symptoms

    Time frame: 28 hours: 4 hours of exposure in EEC then 24 hours post-exposure

    The effect of the exposure on the conjunctivitis response is assessed with Total Ocular Symptom Score (TOSS).

    The TOSS was obtained from the sum of all four individual symptom scores, with a total possible score ranging from 0 (no symptoms) to 12 (maximum symptom intensity).

Sponsors and collaborators

Lead sponsor

Alyatec

Industry

Registry information

Official study title

Validation Study of the ALYATEC Allergen Exposure Chamber (EEC) by Determining the Concentration of Cat Allergen Inducing Early and/or Late Bronchial Response in Asthmatic Subjects Allergic to Cat

Important dates

Study start
2017
Primary completion
2017
Study completion
2017
First posted
Dec 21, 2020
Registry last updated
Dec 21, 2020

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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