Allergenic Extract Standardized Cat Hair AP in an Allergic Rhinitis Model.

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

• Have a TNSS of greater than or equal to 8/12 and at least a 50% drop in PNIF inresponse 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 atvisit 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 responseto the highest allergen concentration at visit 1.

Exclusion Criteria:

• Participant has abnormalities detected on physical examination considered by theinvestigator to be clinically significant.

• Participant has a history of any disease or disorder that, in the judgement of theinvestigator, 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 ofthe 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 seasonalallergen that is present in the outdoor environment during visit 1 and visit 2 andwhich the Principal Investigator judges would impact the outcome of the study.

• Participant has any structural nasal abnormalities or nasal polyps on examination ora history of frequent nose bleeding, as determined by a nasal examination atscreening 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 weeksprior to the NAC visit.

• Participant exhibits any signs or symptoms of a respiratory infection prior to anyvisit, as per Principal Investigator judgement.

• Participant reports a TNSS of greater than or equal to 4 prior to the titrationchallenge at visit 1 or immediately prior to allergen challenge at visit 2, as perPrincipal Investigator judgement.

• Participant reports a TNSS change of greater than 2 from baseline, after the diluentchallenge at visit 1.

• Participants with asthma requiring the use of a short-acting beta agonist greaterthan twice a week (unless for viral asthma) or with severe asthma requiringmaintenance 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 onlow-dose inhaled corticosteroids or PRN inhaled corticosteroid/long-actingbeta-agonist as per Principal Investigator discretion.

• Participant is currently receiving cat allergen specific immunotherapy or concludeda course of cat immunotherapy in the last 3 years.

• Participant has a history of positive test results for HIV, Tuberculosis (not due tovaccination), 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 overthe duration of the study. Participant is unwilling to attend study visits or adhereto the study protocol, in the judgement of the Principal investigator.