on the first visit after joining the study, a series of assessments are performed to confirm eligibility. these include a medical history review, physical examination, and tests of lung function such as the forced expiratory volume in one second (fev1).

questionnaires that measure health status and symptoms, such as the st george’s respiratory questionnaire for chronic respiratory disease (sgrq-c) and the chronic airways assessment test (caat), are completed.

after eligibility is confirmed, the participant is randomly assigned to receive either the investigational drug lunsekimig or a matched placebo. the assignment is double‑blind, meaning neither the participant nor the study staff knows which treatment is given.

the participant receives an injection of the assigned product. the injection is a pre‑filled syringe containing a solution for injection. the dose listed in the protocol is 00.00 mg of lunsekimig per administration. the same procedure is used for the placebo, which contains no active substance.

injections are given at each scheduled study visit according to the study schedule.

the participant attends follow‑up visits at intervals defined by the study protocol. at each visit, lung function tests, vital signs, and safety assessments are performed.

blood samples are collected to measure the serum concentration of lunsekimig and to check for the presence of antidrug antibodies (adas).

the participant reports any adverse events, including serious adverse events (saes) and adverse events of special interest (aesis).

at designated visits, the participant completes questionnaires that evaluate symptoms and health status, such as the shortness of breath questionnaire (e‑rs:coppd) and the st george’s respiratory questionnaire (sgrq‑c).

responses are used to assess changes from baseline in scores that reflect disease impact.

the participant is instructed to report any worsening of respiratory symptoms that require additional treatment. these events are classified as moderate or severe copd exacerbations.

the time to first moderate or severe exacerbation and the annualized rate of exacerbations are recorded throughout the study.

at the end of the study period, which is scheduled to conclude on 2030‑01‑22, the participant attends a final visit. final assessments include lung function testing, laboratory evaluations, and completion of all questionnaires.

the participant receives a summary of the study procedures performed and any remaining study medication is accounted for.