A Multi-centered，Randomized，Double-blind，Placebo-controlled Study to Evaluate the Efficacy and Safety of SHR-1703 in Eosinophilic Asthma

Inclusion criteria

• At least 12 years of age
• A minimum weight of 40kg
• A medical history of at least 1 year that meets the diagnosis of asthma;
• Current treatment with medium- or high- doses of ICS for at least 6 months and using steadily at least 3 months
• Current treatment with an additional controller medication, besides ICS, for at least 3 months and using steadily at least 1 month
• Absolute count of blood eosinophils suggests eosinophilic asthma
• During the screening period and baseline, pre- BD FEV1% < 80%
• During the screening period and baseline, ACQ-6 score indicates asthma poor control
• History of severe asthma exacerbation within the past 12 months prior to screening
• Good compliance with eDiary completion
• Take efficient contraceptive measures
• Voluntarily sign the informed consent form to participate in this study

Exclusion criteria

• With other condition that could lead to elevated eosinophils
• With Clinically significant pulmonary diseases
• With existing immunodeficiency disease
• With other clinically significant diseases that may affect lung function
• With uncontrolled severe cardiovascular and cerebrovascular diseases
• With uncontrolled hypertension and/or diabetes
• With exacerbation, allergic rhinitis or sinusitis attacks, or clinical significant infection requiring intervention during 4 weeks prior to randomization
• Recent major surgeries or surgical plans during the study period, or treatment measures that investigators believe may affect subject evaluation
• Existing parasitic infections
• Diagnosed as malignant tumor within the first 5 years of randomization
• Significant abnormalities in screening period or baseline laboratory tests
• Screening period or baseline ECG QTc prolongation
• Prohibited drugs using during the pre randomization period
• Participated in other clinical trials within 30 days prior to screening and used research drugs containing active ingredients, or was still within 5 half lives of the research drug at the time of screening
• Smoking or quitting smoking for less than 6 months during screening, or previous smoking history ≥ 10 pack years
• History of drug use, alcoholism, or substance abuse within the past year prior to screening
• Allergic or intolerant to IL-5 monoclonal antibodies or other biological agents
• Pregnant or lactating subjects
• Other reasons why the researcher deemed it unsuitable for conducting this experiment