This study is a multicenter, randomized, double-blind, parallel-group, placebo-controlled Phase III clinical trial designed to evaluate the efficacy and safety of TQC2731 injection (420 mg Q4W) in adult subjects with inadequately controlled severe asthma. A total of 660 subjects are expected to be enrolled, with subjects randomized in a 1:1 ratio to receive either TQC2731 (420 mg Q4W) or placebo (Q4W) via subcutaneous (SC) administration.
Sign the informed consent form before the trial to fully understand the purpose, process and possible adverse reactions of the trial;
Age 18 ~ 75 years old, gender is not limited;
Documented physician diagnosis of asthma at least 12 months prior to Visit 1;
Subjects who received high-dose Inhaled Corticosteroids (ICS) in asthma control medications prescribed by their physicians at least 6 months prior to Visit 1;
Have a clinically significant lung disease other than asthma；
Pre-existing autoimmune disease;
A history of known or suspected immunosuppression, including a history of invasive opportunistic infections;
Any disease that has not been determined to be stable by the investigator；