A Phase III Study of MG-K10 in Adolescents With Moderate-to-Severe Atopic Dermatitis

• MG-K10 Injection (Humanized Monoclonal Antibody) (Drug): loading dose (SC) at Week 0, followed by a single dose Q2W through Week 52
• Placebo for MG-K10 (Drug): Initial loading dose (SC), then single dose Q2W through Week 52

Primary outcomes

• Proportion of participants achieving EASI-75 ( ≥75% reduction from baseline ) [week 16]
• Proportion of participants achieving IGA score of 0 (clear) or 1 (almost clear) with a ≥2-point reduction from baseline [week 16]

Secondary outcomes

• Change in Peak Pruritus NRS [Baseline to week 52]
• Proportion of participants achieving EASI-50, EASI-90 [Baseline to week 52]
• Change and percent change from baseline in the Quality of Life Score: CDLQI and EQ-5D-Y-3L scores [Baseline to week 52]
• Incidence in adverse events [Baseline to week 52]

Sex: All, ages: 12 Years to 17 Years

Inclusion Criteria:

1. Diagnosis of Atopic Dermatitis (AD) per American Academy of Dermatology (2014) criteria for ≥6 months;
2. Eczema Area and Severity Index (EASI) ≥16;
3. Investigator's Global Assessment (IGA) ≥3;
4. Body Surface Area (BSA) involvement ≥10%;
5. Peak Pruritus Numerical Rating Scale (NRS) weekly average ≥4;
6. Inadequate response to topical treatments within 6 months or medically inadvisable to use topical treatments.

Exclusion Criteria:

1. Inability to tolerate venipuncture, or a history of needle phobia or hematophobia;
2. Inability to receive subcutaneous injections, such as patients currently receiving anticoagulant therapy, or those with known bleeding disorders or idiopathic thrombocytopenic purpura;
3. Presence of ophthalmic diseases judged by the investigator to be unsuitable for inclusion;
4. Concurrent serious diseases including, but not limited to, cardiovascular, metabolic, or neurological diseases, which, in the opinion of the investigator, render the subject unsuitable for immunosuppressive therapy;
5. History of parasitic infection within 6 months prior to screening;
6. Planned major surgery during the study period;
7. Prior or concomitant treatments meeting any of the following:

   * Use of biologics within 10 weeks prior to randomization or within 5 half-lives (whichever is longer)
   * Use of targeted inhibitors (e.g., JAK inhibitors), systemic glucocorticoids, cyclosporine, or other immunosuppressants (e.g., methotrexate, MMF, azathioprine), phosphodiesterase-4 (PDE4) inhibitors, phototherapy (UV), or systemic Chinese herbal medicine for AD within 4 weeks prior to randomization
   * Use of topical treatments for AD (e.g., topical glucocorticoids, topical calcineurin inhibitors, antibiotic combination creams, or topical Chinese herbal medicine) within 2 weeks prior to randomization
   * Receipt of live or attenuated vaccines within 3 months prior to randomization or plans to receive such vaccines during the study
   * Participation in other clinical trials within 3 months or 5 half-lives (whichever is longer) prior to randomization, or plans to participate in other clinical trials during the study period
   * Systemic anti-infective therapy (oral or intravenous antibacterial, antiviral, or antifungal) within 4 weeks prior to randomization, or current acute or subacute infection indicated by symptoms, signs, or laboratory abnormalities
8. History of alcohol or drug abuse within 6 months prior to screening; Known allergy or intolerance to any component of the investigational product.
9. Other conditions that, in the opinion of the investigator, make the subject unsuitable for participation in the study.