STUDY DESIGN A single-center prospective before-and-after study evaluating the effect of Alutard SQ Dog in 40 men and women with moderate-to-severe dog allergy. Participants will serve as their own controls.

STUDY OUTLINE

The study will begin in the fall of 2026 and will be conducted over a one-year period. At baseline, participants will be asked to record their allergic symptoms, and assessments of lung function and nasal airflow will be performed. Blood samples will also be collected.

Following the baseline assessments, participants will undergo allergen provocation by entering a facility containing dogs. After a 30-minute exposure to dogs, participants will again be asked to record their allergic symptoms and will undergo the same assessments performed at baseline.

Allergen immunotherapy (AIT) with Alutard SQ Dog will then be initiated according to the standard treatment regimen and continued for one year. At the end of the treatment period, the same provocation procedure and assessments will be repeated. Participants will enter a facility containing dogs, followed by symptom recording and evaluation of lung function, nasal airflow, and relevant laboratory parameters.

• Lung function assessed by Peak Expiratory Flow (PEF)
• Nasal airflow assessed by Peak Nasal Inspiratory Flow (PNIF)
• Serum levels of allergen-specific IgE to Can f 1, Can f 2, Can f 3, Can f 4, Can f 5, and Can f 6
• Symptom severity assessed using a Visual Analogue Scale (VAS)

Inclusion Criteria

The subject has provided written informed consent to participate in the study.

• Age 18-50 years.
• Moderate-to-severe allergic symptoms upon exposure to dogs.
• Dog allergy confirmed by positive specific IgE.
• Considered suitable by the investigator for treatment with Alutard SQ Dog in accordance with the approved Summary of Product Characteristics (SmPC).
• Female subjects of childbearing potential must use adequate contraception.
• A negative pregnancy test must be obtained prior to enrolment.

Exclusion Criteria

• Pregnancy or breastfeeding.
• Autoimmune or connective tissue disease.
• Cardiovascular disease.
• Hepatic disease.
• Renal disease.
• Malignancy.
• Upper airway disease (e.g., non-allergic sinusitis or nasal polyposis).
• Chronic obstructive or restrictive lung disease.
• Treatment with medications that may interfere with the immune response.
• Previous immunotherapy or chemotherapy.
• Significant chronic disease.
• Major metabolic disease.
• Alcohol or substance abuse.
• Mental or cognitive incapacity that may impair compliance with study procedures.
• Known or suspected hypersensitivity to the study product.
• Suspected or confirmed bacterial infection.
• Clinically relevant allergy to house dust mite.
• Current dog ownership.
• Any condition that, in the investigator's opinion, may make participation, follow-up, or study assessments inappropriate.
• Any subject considered unsuitable for enrolment according to the principles of the Declaration of Helsinki.

Pseudonymized aggregate data will be published. Pseudonymized individual participant data will be made available upon reasonable request.

Raw study data will be retained for 10 years following study completion.

Qualified researchers may request access to pseudonymized individual participant data for the purpose of verifying the study results. Data will be provided upon reasonable request after publication of the study results and will be shared electronically by email.