Efficacy and Safety of PQ Grass in Subjects With Seasonal Allergic Rhinitis and/or Rhinoconjunctivitis Induced by Grass Pollen

Inclusion Criteria

• Capable of giving signed informed consent as described in Appendix 1 which includes compliance with the requirements and restrictions listed in the ICF (informed consent form) and in this clinical trial protocol and to attend required clinical trial visits.
• Subject who has a signed and dated ICF.
• Subject must be 18 to 65 years of age inclusive, at the time of signing the ICF.
• Male or female.
• Female subjects who are not of childbearing potential (defined as at least 12 months natural spontaneous amenorrhoea, or at least 6 weeks following surgical menopause/permanent sterilisation [hysterectomy, bilateral oophorectomy and bilateral salpingectomy]) or females of childbearing potential who agree to comply with the contraceptive requirements of the clinical trial protocol.
• Good general health, as determined by the Investigator, based on a medical evaluation, including medical history, physical examination, mental status assessment and laboratory tests. A subject with a clinical abnormality or laboratory parameters outside the reference range for the population being studied may be included only if the Investigator agrees that the finding is unlikely to introduce additional risk factors and will not interfere with the clinical trial procedures.
• Positive history of moderate to severe symptoms of SAR/rhinoconjunctivitis ascribed to grass (Pooideae) pollen exposure of at least 2 seasons duration, despite having received allergy pharmacotherapy (e.g., antihistamines, nasal corticosteroids, leukotriene modifiers, etc.) during the last 2 consecutive grass pollen seasons prior to the clinical trial, confirmed by subject records.

Please note: Subjects with asthma may be included, but the asthma must be well controlled (according to current Global Initiative for Asthma [GINA] guidelines [GINA 2022]).

• A positive SPT (skin prick test) to histamine (wheals [longest diameter] ≥3 mm) and a negative SPT to the negative control (wheal diameter = 0 mm) at screening.
• A positive SPT for grass pollen (wheals [longest diameter] ≥3 mm).
• Grass specific IgE (immunoglobulin E) class ≥2 as documented by an ImmunoCAP test at screening.
• Forced expiratory volume in one second (FEV1) ≥70% of predicted, with a FEV1/forced vital capacity (FVC) ratio >75% and PEFR (peak expiratory flow rate) ≥70% of predicted at screening.

Exclusion Criteria

• Pregnant or lactating subject.
• Presence of any medical history of moderate to severe allergy symptoms (verified by a positive SPT at screening or positive specific IgE [≥2] at screening) to any other seasonal allergen (other than grass) or perennial allergens.

Exception: Period 1, Period 2 and Period 3 of the entire clinical trial will be conducted outside of the pollen season(s) of concern or perennial allergies are irrelevant due to avoidance measures (e.g., cats and dog allergy). Subjects with mild allergy symptoms (only) to any other allergen apart from grass may be included at the discretion of the Investigator. In countries in Europe where Bermuda grass is present, any medical history of moderate to severe allergy symptoms to Bermuda grass (verified by a positive SPT or positive specific IgE [Class ≥2]), will also represent a reason for exclusion as it will not be possible to conduct Period 1, Period 2 and Period 3 of the entire clinical trial outside of Bermuda grass pollen season. Albeit Bermuda grass being commonly defined as a grass, it belongs to the Poaceae family, while the sentence (other than grass) in Exclusion criterion #2 refers to grass of Pooideae subfamily (as defined in Inclusion criterion #7).

• Subjects at US clinical trial sites in regions where southern grasses (Bahia grass, Bermuda grass or Johnson grass) are the dominant grasses and the main cause of grass allergy symptoms with a positive SPT to any of the 3 grasses (irrespective of the severity of symptoms).
• Moderate to severe symptoms during the 3 years prior to Visit 1 to any o