A Study to Evaluate the Pharmacodynamic, Efficacy and Safety of SHR-1703 in Asthma Patients With Eosinophil Phenotype

Prior treatment

• Diagnosed Malignant tumor within 5 years prior to randomization;
• Used non-selective β-blockers within 1 week prior to randomization;
• Used either 5-lipoxygenase inhibitor or Phosphodiesterase-4 inhibitor within 1 week prior to randomization;
• Blood donation or massive blood loss, or transfusion of blood products or immunoglobulins within 4 weeks prior to randomization;
• Live attenuated vaccine inoculated within 4 weeks before randomization;
• Allergen Immunotherapy within 8 weeks prior to randomization；
• Used systemic immunosuppressants or immunomodulators, or biologics or Th2 cytokine inhibitors within 12 weeks prior to randomization or within 5 half-lives of the drug;
• Bronchial thermoplasty within 1 year prior to randomization；
• Subjects have planned Surgery or other medical procedures that may affect evaluation during the study period;
• History of drug or substance abuse or alcohol abuse within 1 year prior to screening;
• Subjects participated another clinical studies and received active drug within 30 days or 5 half-lives prior to screening;

Other illness

• Subjects with Clinically significant pulmonary diseases；
• Subjects with other diseases that could lead to elevated eosinophils；
• Poorly controlled hypertension;
• Subjects with severe cerebrovascular disease;
• Subjects with infection history requiring clinical intervention；
• Subjects with parasitic infection；
• Current smokers or ex-smokers who have given up smoking for \<6 months ，or positive smoke test, and/or have a smoking pack history of \> 10 pack years;
• Subjects have a known history of hypersensitivity or intolerance to anti-IL-5 mabs or other biological agents;
• Other conditions unsuitable for participation in the study per investigator judgement.

Lab values

• Subjects with significant laboratory abnormality at screening；
• Subjects have prolonged QTc interval or other electrocardiogram abnormality with significant safety risk at screening;

Other

• Subjects with Immunodeficiency；
• Subjects is pregnant, lactating,or planning to become pregnant;

• Aged 18 to 75years (inclusive).
• Weight ≥40 kg.
• History of asthma≥ 1 year.
• Documented treatment with Medium or high daily dose inhaled corticosteroid with additional controller medication within the 3 months prior to randomization.
• Previously confirmed history of one or more asthma exacerbations within 1 year prior to randomization.
• Blood eosinophils of ≥150 cells/µL at screening and baseline.
• Pre-Bronchodilator FEV1% pred≥40% and\<80% at screening and baseline.
• Asthma Control Questionnaire-6 score≥1.5.
• Use highly effective contraceptive measures.
• Willing to sign the informed consent form to participate in this study.