Inclusion Criteria:
* Aged 18 to 80 on the day of signing the informed consent.
* With a diagnosis of asthma for at least 6 months.
* With pre-BD FEV1 ≥ 50% of the predicted value at the Screening visit (see section 18.6 for calculation of the predicted value for FEV1).
* Having blood eosinophil counts ≥ 150 cells/μL at the Screening visit.
* Participants who meet any of the following asthma criteria at the Screening visit:
* Moderate asthma-1 (i.e., step 3 in asthma treatment steps in adults and adolescents from 2025 GINA guideline):
* Moderate asthma-2 (i.e., step 4 in asthma treatment steps in adults and adolescents from 2025 GINA guideline):
* Severe asthma (i.e., step 5 in asthma treatment steps in adults and adolescents from 2025 GINA guideline, except for biologic therapies):
Exclusion Criteria:
* A current smoker or quit smoking ≤ 0.5 years at Screening visit.
* With serious underlying chronic illness or severe systemic disease, including but not limited to systemic lupus erythematosus, at the investigator's discretion.
* With a current malignancy or previous history of cancer in remission for less than 5 years prior to Screening visit (Subject will not be excluded if he/she had localized carcinoma of the skin that was resected for cure).
* With chronic heart failure in New York Heart Association class III to IV.
* With clinically severe lung disease, including but not limited to cystic fibrosis, chronic bronchitis (chronic obstructive pulmonary disease other than asthma), chronic respiratory infection, lung cancer, current infection, active tuberculosis infection, bronchiectasis, pulmonary fibrosis, bronchopulmonary aspergillosis, or diagnoses of emphysema.
* With arrhythmia, myocardial infarction, or stroke within the last 3 months prior to the Screening visit.
* With a recent respiratory tract infection within 4 weeks prior to the Screening visit.
* Received chronic oxygen therapy within one month prior to the Screening visit.
* With any nasal conditions that could interfere with drug absorption or confound the efficacy or safety assessments.
* Immunosuppressive treatment, including but not limited to methotrexate, troleandomycin, cyclosporine, and azathioprine within 3 months prior to the Screening visit and throughout the study.
* Use of systemic corticosteroids (including regular oral corticosteroids or intramuscular long-acting depot corticosteroids) at daily average doses greater than 7.5 mg prednisone or equivalent for the past 3 months prior to the Screening visit.
* Having or planning to be vaccinated with live (attenuated) vaccine within 1 month prior to the Screening visit and throughout the study.
* Having received immunotherapy including but not limited to monoclonal antibodies, within 3 months prior to the Screening visit and throughout the study.
* Having previously received AD17002.
* Having received other IP or investigational intervention (non-AD17002), including investigational formulations of marketed products, within the past 30 days or 5 half-lives of the medication, whichever is longer, prior to the Screening visit.
* Requiring add-on biologic therapy, such as anti-IgE, anti-IL-5/5R, anti-IL-4Rα, and anti-thymic stromal lymphopoietin treatment.
* Having experienced a life-threatening asthma attack or an occurrence of any clinical deterioration of asthma that resulted in emergency treatment, hospitalization due to asthma, or treatment with high-dose systemic corticosteroids (prednisolone ≥ 40 mg/day or equivalent for ≥ 5 days) within 1 month prior to the Screening visit.
* Having a history of anaphylaxis with cardiorespiratory symptoms, triggered by prior immunotherapy, an unknown cause, or an inhalant allergen.
* Being pregnant or breastfeeding.
* Planning to become pregnant or breastfeed throughout the study.
* A known history of allergy, hypersensitivity, or intolerance to any component of IP, rescue medications, or self-injectable epinephrine.
* Any clinically significant abnormalities in physical examination, vital signs, hematology, biochemistry, or urinalysis that, in the investigator's opinion, may pose a risk to the patient's safety, affect study outcomes, or hinder the patient's ability to complete the study.
