Dose-Ranging Study of LQ036 Single-Domain Antibody Nebulization Solution in Poorly Controlled Asthma

What is the goal of this study? The goal of this clinical trial is to find out whether the study drug LQ036 (a nebulized solution taken by inhaling through a nebulizer) works to improve lung function and asthma control in people whose asthma is not well controlled. The study will also learn about the safety of LQ036, how the body processes it, and whether the body develops an immune response to it. What are the main questions? The most important question is: • Does LQ036 improve lung function (measured by FEV₁ - the amount of air you can blow out in one second) more than a placebo at Week 12? Other important questions include: * Does LQ036 improve lung function at other time points (weeks 1, 2, 4, 8, 16, 20, 24)? * Does LQ036 reduce asthma attacks (sudden worsening of asthma that needs extra treatment)? * Does LQ036 help people use less rescue medication (inhaler for quick relief) and have more days without asthma symptoms? * Does LQ036 improve scores on asthma control and quality of life questionnaires? * What medical problems do participants have when taking LQ036?

Inclusion Criteria: * Outpatients, aged 12 to 75 years inclusive, male or female, with body mass index (BMI) between 18 and 30 kg/m² inclusive. For participants aged 12 to 17 years, body weight must be ≥30 kg. * Diagnosed with bronchial asthma according to the 2025 Global Initiative for Asthma (GINA) guidelines prior to screening, with a documented history of asthma for ≥12 months. * For at least 3 months prior to screening, the participant has used inhaled corticosteroids (ICS) combined with at least one controller medication, and has maintained a stable treatment regimen and dosage for at least 1 month prior to screening. Low, medium, and high maintenance doses of ICS are defined according to the 2025 GINA guidelines (if multiple nebulized or combined administration methods are used, doses are to be combined). * At screening, pre-bronchodilator FEV₁ is ≥40% and \1.5 × ULN. * Pregnant or breastfeeding women; women planning to become pregnant during the study or within 3 months after the end of the study; fertile women or men who, in the investigator's judgment, cannot use medically accepted reliable contraception from signing informed consent until 3 months after the last dose of study drug; positive pregnancy test result at screening or before randomization for fertile women. * Participation in another clinical study of a drug or device within 3 months prior to signing informed consent, with use of investigational drug/device; or still within the follow-up period of another clinical study or within 5 half-lives of the investigational drug (whichever is longer) at the time of signing informed consent. * History of blood donation or significant blood loss, blood transfusion, or use of blood products within 3 months prior to screening. * Known or suspected non-compliance, drug abuse, substance abuse, or alcohol abuse (daily pure alcohol intake \>40 g for males, \>20 g for females). * Any condition that, in the investigator's judgment, makes the participant unsuitable for participation in this clinical trial.