Overview

The goal of this study is to learn if a cat allergen extract known as Allergenic Extract Standardized Cat Hair Acetone Precipitated (AP Cat) can induce allergic rhinitis (AR) in a nasal allergen challenge model in cat-allergic people. The main questions this study aims to answer are:

1. Does AP Cat induce nasal symptoms of allergic rhinitis in cat-allergic participants when delivered intranasally?
2. Does AP Cat reduce elements in the blood and nose that are known to be associated with allergies?

Both allergic and non-allergic participants will be recruited into this study.

Allergic participants will:

• Be challenged with AP Cat via the Nasal Allergen Challenge (NAC), which involves administration of this allergen extract directly into the nose.
• Have nasal fluid and blood samples collected at various timepoints up to 24 hours after exposure to the allergen in the NAC.
• Visit the study site three separate times:
  1. At screening (Visit 1), to determine eligibility to participate in this study
  2. At the baseline NAC visit (Visit 2)
  3. At the 24-hour post-NAC follow-up visit (Visit 3)
• Complete nasal symptom questionnaires.
• Complete a questionnaire about their regular exposure to cats.

Non-allergic participants will:

• Be challenged with AP Cat via the NAC, which involves administration of this allergen extract directly into the nose.
• Have nasal fluid and blood samples collected at various timepoints up to 24 hours after exposure to the allergen in the NAC.
• Visit the study site three separate times:
  1. At screening (Visit 1), to determine eligibility to participate in this study
  2. At the baseline NAC visit (Visit 2)
  3. At the 24-hour post-NAC follow-up visit (Visit 3)
• Complete nasal symptom questionnaires.

This study will compare the nasal symptoms and allergic markers collected from the nasal fluid and blood samples between allergic and non-allergic participants at baseline and various timepoints post-NAC exposure.

Eligibility

Inclusion Criteria:

To be considered for inclusion in this study, all participants must be:

• A healthy, ambulatory male, female, or intersex volunteer between the ages of 18 to 70 years of age.
• Able to understand and willing to provide written informed consent.
• Able and willing to comply with study requirements.

To be enrolled as an allergic participant, participants must:

• Have a minimum 2-year history of AR symptoms upon exposure to cats.
• Have a positive skin prick response to AP cat allergen, defined as a wheal diameter ≥ 5 mm compared to the negative control wheal. This result must be achieved at visit 1.
• Have a TNSS of greater than or equal to 8/12 and at least a 50% drop in PNIF in response to the allergen titration challenge at visit 1.

To be enrolled as a non-allergic participant, participants must:

• Produce a negative skin test response to a panel of relevant aeroallergens tested at visit 1 or within 12 months before visit 1 at the research site.
• Produce a negative Nasal Allergen Challenge, defined by a TNSS response of less than 4/12 and a PNIF reduction of less than or equal to 20% after 10 minutes in response to the highest allergen concentration at visit 1.

Exclusion Criteria:

• Participant has abnormalities detected on physical examination considered by the investigator to be clinically significant.
• Participant has a history of any disease or disorder that, in the judgement of the investigator, would impact the participant's safety or the results of the study.
• Participant has a significant history of alcohol or drug abuse in the judgment of the Principal Investigator or delegate.
• Participant is pregnant, lactating, or actively trying to become pregnant.
• Participant is unable to comply with the washout periods for restricted medications.
• Participant has signs/symptoms of active seasonal AR or is allergic to a seasonal allergen that is present in the outdoor environment during visit 1 and visit 2 and which the Principal Investigator judges would impact the outcome of the study.
• Participant has any structural nasal abnormalities or nasal polyps on examination or a history of frequent nose bleeding, as determined by a nasal examination at screening and prior to the NAC, in the judgement of the principal investigator.
• Participant has undergone nasal surgery within the previous 3 months before visit 1.
• Participant has experienced an upper or lower respiratory infection within 2 weeks prior to the NAC visit.
• Participant exhibits any signs or symptoms of a respiratory infection prior to any visit, as per Principal Investigator judgement.
• Participant reports a TNSS of greater than or equal to 4 prior to the titration challenge at visit 1 or immediately prior to allergen challenge at visit 2, as per Principal Investigator judgement.
• Participant reports a TNSS change of greater than 2 from baseline, after the diluent challenge at visit 1.
• Participants with asthma requiring the use of a short-acting beta agonist greater than twice a week (unless for viral asthma) or with severe asthma requiring maintenance high doses of inhaled or oral corticosteroids or biologic therapy (Omalizumab/Mepolizumab/Resilizumab).
• Participant has a history of cat allergen induced asthma, unless well controlled on low-dose inhaled corticosteroids or PRN inhaled corticosteroid/long-acting beta-agonist as per Principal Investigator discretion.
• Participant is currently receiving cat allergen specific immunotherapy or concluded a course of cat immunotherapy in the last 3 years.
• Participant has a history of positive test results for HIV, Tuberculosis (not due to vaccination), Hepatitis B (not due to vaccination) or Hepatitis C.
• Participant has received an investigational product within the previous 30 days.
• Participant is unable and/or unlikely to comprehend and/or follow the protocol over the duration of the study. Participant is unwilling to attend study visits or adhere to the study protocol, in the judgement of the Principal investigator.