A randomized, double-blind, placebo-controlled Phase III clinical trial on the efficacy and safety of MG-K10 humanized monoclonal antibody injection in adolescent and adult patients with moderate to severe asthma.

A randomized, double-blind, placebo-controlled Phase III clinical trial on the efficacy and safety of MG-K10 humanized monoclonal antibody injection in adolescent and adult patients with moderate to severe asthma is planned to enroll 504 subjects. These patients will receive multiple subcutaneous injection treatments. This study is divided into: a screening period of 1 week, a lead-in period of 4 weeks, a treatment period of 52 weeks, and a follow-up period of 8 weeks.

Inclusion criteria:

1. Age between 12~75 years old (including the critical value), male and female, weight ≥ 30kg;
2. Diagnosed with asthma for at least 1 year and current disease status that meets the diagnostic criteria of the 2024 GINA guidelines, and:

1) Subjects have received moderate-high dose ICS therapy for at least 2 consecutive months before screening (see Appendix 5 for details, fluticasone propionate ≥250 μg twice a day, or an equivalent dose of ICS, no more than 2000 μg/day or equivalent dose of fluticasone propionate) combined with 1 control drug (such as LABA, LTRA, LAMA or extended-release theophylline), and maintained a stable treatment regimen and dose therapy for ≥ 1 month before baseline. Subjects using the third control drug can also participate in the study, but the subjects must also use the third control drug for at least 2 consecutive months before screening, and maintain a stable treatment regimen and dose treatment ≥ 1 month before baseline; 2) 1-second forced expiratory volume (FEV1) before bronchodilator use at the screening and baseline visits, measured ≤ 80% of the normal predicted value for adults and 90% of the normal predicted value ≤ for adolescents; 3) Asthma Control Questionnaire-5 (ACQ-5) score ≥ 1.5 points at the screening and baseline visits; 4) Must have experienced ≥ 1 acute exacerbation event within 12 months prior to screening: need to receive 1 ≥ systemic glucocorticoids (oral or intravenous) treatment due to asthma exacerbation or need hospitalization/emergency treatment; 5）A positive bronchodilator test (a ≥12% increase in FEV1 after inhalation of bronchodilators and an absolute increase in FEV1 ≥200 mL) will be acceptable for bronchodilator test results within 24 months prior to screening； Positive bronchodilator test (after inhaling a bronchodilator, the forced expiratory volume in one second (FEV1) increases by ≥12%, and the absolute value of FEV1 increases by ≥200 mL). The results of the bronchodilator test conducted within 24 months before screening are acceptable.

3.The subjects (including adolescents aged 12 years old ≤ age < 18 years old) agree that they themselves and their partners will adopt effective contraceptive measures from the signing of the Informed Consent Form (ICF) until 6 months after the last administration of the drug.

4.The subject and his/her guardian (applicable to adolescents aged 12 years old ≤ age < 18 years old) are able to understand the procedures and methods of this study, willing to sign the Informed Consent Form, strictly abide by the clinical research protocol to complete the study, and capable of independently completing the study-related questionnaires.

Exclusion criteria:

1. Subjects with known hypersensitivity to the investigational product or its excipients;
2. Subjects who, within 1 month prior to screening and drug administration, have required systemic glucocorticoid therapy (oral or intravenous) for asthma exacerbation at least once, or have required hospitalization/emergency treatment due to asthma exacerbation.
3. Subjects who, within 1 month prior to screening and drug administration, have required at least one course of systemic glucocorticoid therapy (oral or intravenous administration) for asthma exacerbation, or have required hospitalization or emergency treatment due to asthma exacerbation.
4. Subjects who have received systemic glucocorticoid therapy from 1 month before screening until drug administration (excluding those with topical, ophthalmic, or intranasal glucocorticoid use)
5. Subjects who have received intravenous immunoglobulin (IVIG) therapy or allergen-specific immunotherapy (SIT) within 1 month prior to drug administration.
6. Subjects who have undergone major surgery within 8 weeks prior to screening have scheduled major surgery during the study period, including inpatient and day-case outpatient procedures.
7. Subjects with a history of substance abuse or illicit drug use.
8. Subjects with any other conditions that, in the investigator's judgment, may compromise subject safety or trial integrity.