This study is a phase II study of RC1416 in subjects with severe uncontrolled asthma. The purpose of the study is to evaluate efficacy and safety of RC1416 in subjects with severe uncontrolled asthma.

RC1416 is a bispecific homodimer nanobody .It is being developed by Nanjing RegeneCore Biotech Co., Ltd. as a potential therapy for asthma. A total 195 severe uncontrolled asthma subjects will be enrolled in three groups to access the efficacy and safety of RC1416.

Inclusion Criteria:

• Male or female aged 18 and 75 years.
• Diagnosed with asthma for at least 1 year, and the current disease status meets the diagnostic criteria of the 2024 GINA guidelines.
• Have received medium-to-high dose ICS therapy for at least 3 consecutive months prior to screening, and maintained a stable treatment regimen and dose for ≥1 month prior to baseline.
• Pre-bronchodilator forced expiratory volume in 1 second (FEV1) measurement ≤80% of the predicted normal value at both the screening and baseline visits.
• Asthma Control Questionnaire-6 (ACQ-6) score ≥1.5 at both the screening and baseline visits.
• Must have experienced ≥1 severe asthma exacerbation event within the 12 months prior to screening.
• Positive bronchodilator reversibility test.

Exclusion Criteria:

• Individuals with a known history of allergy to the investigational product or its excipients.
• Clinically diagnosed with chronic obstructive pulmonary disease (COPD) or other lung diseases that may impair lung function .
• Experienced a severe asthma exacerbation event from within 1 month prior to screening until before dosing.
• Used systemic corticosteroids within 1 month prior to screening.
• Had a pulmonary or other site infection requiring intravenous antibiotics, antifungals, or antivirals from within 1 month prior to screening until before dosing.
• Used traditional Chinese medicine with anti-asthmatic effects within 1 month prior to screening.
• Underwent major surgery within 8 weeks prior to screening or plans to undergo major surgery during the study period.
• With a history of malignancy within the past 5 years .
• Active or incompletely treated tuberculosis
• Used biologic/systemic immunosuppressant/immunomodulators within 12 weeks or 5 half-lives prior to screening.
• Diagnosed active parasitic infection; suspected parasitic infection or high risk of infection.
• Abnormal 12-lead electrocardiogram (ECG) at screening. The above information is not intended to contain all considerations relevant to a patient's potential participation in a clinical trial