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Completed

NCT Number: NCT06104293

Determination of Grass Pollen Allergen Concentration Inducing Rhinoconjunctivitis Symptoms in Subjects Allergic to Grass Pollen in ALYATEC Allergen Exposure Chamber

The aim of this study is to determine the optimal concentration of grass pollen allergens inducing rhinoconjunctivitis in subjects allergic to grass pollen in ALYATEC allergen exposure chamber.

Four concentrations of grass pollen allergen (Phl p 5) are tested during 3-hour exposures: 0, 30, 60 and 90 ng/m3.

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Key information

Age range

18 year–65 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

ALYATEC

Strasbourg, France

Who can participate

Healthy volunteers accepted: No

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

Main Inclusion Criteria:

  • Subjects with symptoms of allergic rhinoconjunctivitis to grass pollen without associated asthma, requiring anti-allergic treatment for at least 2 consecutive pollen seasons;
  • Subjects with positive skin prick tests to grass pollen extracts (Phleum pratense): papule diameter ≥ 5 mm compared to the negative control (NaCl reaction < 2 mm));
  • Subjects with Phl p 5 specific recombinant Immunoglobulin E ≥ 0.70 kIU/L;
  • Forced expiratory volume in 1 second (FEV1) ≥ 70% of predicted value at screening and before allergenic exposures;
  • Women of childbearing age must have a negative pregnancy test at screening and before exposure visits;

Main Exclusion Criteria:

  • Specific immunotherapy (SIT) to grass pollen allergens for more than one month in the 3 years preceding the screening visit;
  • Ongoing specific immunotherapy to another allergen
  • History of anaphylaxis following exposure to grass pollen or grass SITs;
  • Asthma
  • Ear, Nose & Throat or ocular surgical intervention in the 6 months preceding inclusion;

Treatment and study plan

Grass Pollen Allergen Exposure

Other

After the screening visit, subjects are randomized into 3 groups presenting a sequence of allergen concentrations with randomly defined concentrations of Ph l p 5 (0, 30, 60 and 90 ng/m3).

Each participant undergo four different 3-hour exposure sessions to grass pollen allergen corresponding to the four different allergen concentrations.

Primary outcomes

  1. Optimal concentration of grass allergens (Phl p 5 in ng/m3) to induce a positive rhino-conjunctivitis response in subjects allergic to grass pollen during 3 hours of exposure to grass pollen allergens in the ALYATEC Environmental Exposure Chamber (EEC)

    Time frame: 0 to 3 hours

    The optimal concentration of grass pollen allergens Phl p 5 in ng/m3 will be determined by evaluating the Area Under the Curve (AUC) of the rhino-conjunctivitis TSS (Total Symptoms Score).

    The value of the TSS varies from 0 (no symptom) to 24 (highest symptoms)

Secondary outcomes

  1. Time to obtain a rhino-conjunctivitis response during the 3 hours of exposure to grass pollen allergens in the ALYATEC EEC

    Time frame: 0 to 3 hours

    The exposure time will be determined by the time necessary to obtain the first uncorrected TSS (Total Symptoms Score) score ≥ 12 and corrected ≥ 10.

    The value of the TSS varies from 0 (no symptom) to 24 (highest symptoms)

  2. Optimal concentration of grass allergens (Phl p 5 in ng/m3) to induce a positive rhinitis response in subjects allergic to grass pollen during 3 hours of exposure to grass allergens in the ALYATEC Environmental Exposure Chamber (EEC)

    Time frame: 0 to 3 hours

    The optimal concentration of grass pollen allergens Phl p 5 in ng/m3 will be determined by evaluating the Area Under the Curve (AUC) of the rhinitis-related questions of the TSS (nasal congestion, rhinorrhea, nasal itching, sneezing).

    The value of the rhinitis-related questions of the TSS varies from 0 (no symptom) to 12 (highest symptoms)

  3. Frequency of bronchial response during 3 hours of exposure in the ALYATEC EEC

    Time frame: 0 to 3 hours

    The frequency of bronchial response will be assessed by determining the number of subjects presenting at least one drop of FEV1 ≥ 20% during the 3 hours of exposure in ALYATEC EEC.

  4. Use of concomitant medications during and after exposures in the EEC ALYATEC

    Time frame: 0 to 24 hours

    The use of concomitant medications will be assessed by determining the number of subjects using at least one treatment during and up to 24 hours after the exposure.

Sponsors and collaborators

Lead sponsor

Alyatec

Industry

Registry information

Important dates

Study start
2022
Primary completion
2023
Study completion
2023
First posted
Oct 27, 2023
Registry last updated
Nov 27, 2023

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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