Study on the Safety and Efficacy of PA9159 Inhalation Aerosol for the Treatment of Adult Bronchial Asthma

Inclusion Criteria: * Aged 18 to 75 years inclusive, regardless of gender; * According to the definition in the Chinese "Guidelines for Prevention and Treatment of Bronchial Asthma (2020 Edition)," subjects diagnosed with bronchial asthma, including those with an initial diagnosis of asthma, or those diagnosed with asthma during childhood or adolescence with stable condition who have not received long-term treatment but exhibit significantly more pronounced symptoms in adulthood and/or recently compared to the past; * Pre-randomization, pulmonary function tests show 60% ≤ FEV1% predicted ≤ 85%; * Any objective test result indicating variable airflow limitation conducted within 1 year prior to screening is positive, or the bronchodilator test during the screening period is positive, i.e., an increase in FEV1 ≥ 12% and an absolute increase in FEV1 ≥ 200 mL 15-30 minutes after inhaling 400 μg salbutamol (if the bronchodilator test result does not meet the positive threshold, a repeat bronchodilator test is allowed within 14 days after the test \[excluding the test day\]); or the bronchial provocation test is positive, i.e., a decrease in FEV1 ≥ 20% after inhaling a provocant (methacholine or histamine); or the average daily diurnal variability of peak expiratory flow (PEF) (calculated as the sum of daily PEF diurnal variability over 7 consecutive days divided by 7) \> 10%; * Voluntarily sign the informed consent form. Exclusion Criteria: * Subjects who are unable to correctly…