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

Not Applicable

Completed

• Conditions: Allergy; Allergic Asthma; Allergy to Cats
• Interventions: Other: Exposure to Placebo; Other: Exposure to a single dose of cat allergen; Other: Exposure to dose A and dose B of cat allergen

• Registration Number: NCT04678063
• Lead Sponsor: Alyatec

Brief Summary

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.

Detailed Description

Not available

Study Timeline

• Study Start: 2017-04-10
• Primary Completion: 2017-06-15
• Study Completion: 2017-07-11
• Status Verified: 2020-12
• Study First Submitted: 2020-12-04
• Study First Submitted QC: 2020-12-16
• Last Update Submitted: 2020-12-16
• Study First Posted: 2020-12-21
• Last Update Posted: 2020-12-21

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 31

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

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Asthmatic allergic subjects not sensitized to cat	Exposure to a single dose of cat allergen	Group B will be exposed to placebo at exposure 1, and then at exposure 2, the concentration of cat allergens corresponding to the dose that achieved the main objective (Dose A or B).
Asthmatic allergic subjects not sensitized to cat	Exposure to Placebo	Group B will be exposed to placebo at exposure 1, and then at exposure 2, the concentration of cat allergens corresponding to the dose that achieved the main objective (Dose A or B).
Asthmatic subjects allergic to cat	Exposure to Placebo	Group A will be randomized into 2 subgroups of 10 subjects: group A1 and A2. Both subgroupes will be exposed to placebo on exposure 1 then Subgroup A1 will be exposed to dose A on exposure 2 and dose B on exposure 3. Subgroup A2 will be exposed to dose B on exposure 2 and dose A on exposure 3. Dose A and B correspond to different Allergen concentration in the EEC.
Asthmatic subjects allergic to cat	Exposure to dose A and dose B of cat allergen	Group A will be randomized into 2 subgroups of 10 subjects: group A1 and A2. Both subgroupes will be exposed to placebo on exposure 1 then Subgroup A1 will be exposed to dose A on exposure 2 and dose B on exposure 3. Subgroup A2 will be exposed to dose B on exposure 2 and dose A on exposure 3. Dose A and B correspond to different Allergen concentration in the EEC.

Primary Outcome Measures

Name	Time	Method
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.	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 Outcome Measures

Name	Time	Method
Evaluate the allergen concentration in the EEC	4 hours exposure in EEC	The measurement of allergen concentration is performed with several sensors positioned in the chamber.
Evaluate the effect of the exposure on conjunctivitis symptoms	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).
Evaluate the safety of allergenic exposure in EEC	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).
Evaluate the specificity of the bronchial response	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.
Evaluate the effect of the exposure on rhinitis symptoms	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).

Trial Locations

Locations (1)

Alyatec; 🇫🇷 Strasbourg, Grand Est, France