This period begins after signing the consent form and lasts until randomization. During this time, your eligibility for the study will be confirmed through several visits.

At the first visit, your lung function will be tested using a breathing test called spirometry, which measures how much air you can breathe out and how quickly. You will perform this test before and after receiving a medication that opens your airways to see if your breathing improves by at least 12% and 200 milliliters.

A blood sample will be taken to measure the level of certain white blood cells called eosinophils. Your eosinophil count must be at least 150 cells per microliter, or you must have had a count of at least 300 cells per microliter in the past 12 months.

A breathing test called FeNO will be performed, which measures the level of nitric oxide in your breath. This helps determine the type of inflammation in your airways. Your FeNO level must be at least 25 parts per billion.

You will complete a questionnaire called the Asthma Control Questionnaire to assess how well your asthma is controlled. Your score must be at least 1.5 at two different visits during this period.

You will be given an electronic device to record your asthma symptoms twice daily in an Asthma Symptom Diary. You must complete at least 7 morning and 7 evening entries in the last 10 days of this period.

You will need to demonstrate proper technique in using your inhaler, peak flow meter, and performing spirometry tests.

You must show at least 70% compliance with taking your usual asthma medications during this period.

This screening period includes multiple visits to ensure you meet all requirements before starting the study medication.

Once you complete the screening period successfully, you will be randomly assigned to receive either WIN378 or a placebo. A placebo looks identical to the study medication but contains no active ingredient.

This is a double-blind study, which means neither you nor your doctor will know which treatment you are receiving.

The study medication WIN378 is an antibody that targets a protein called TSLP, which is involved in the inflammation associated with asthma.

The medication will be given as an injection under the skin, similar to how insulin is administered for diabetes.

This visit marks Week 0 or Day 1 of the treatment period.

The treatment period will last for 48 weeks.

You will receive injections of either WIN378 or placebo under your skin at scheduled visits throughout this period.

You must continue taking your regular asthma controller medications as prescribed by your doctor throughout the study.

You will continue to complete the Asthma Symptom Diary twice daily using the electronic device provided.

Regular study visits will be scheduled throughout the 48 weeks to monitor your condition and collect data.

At various visits during the 48-week treatment period, several tests and assessments will be performed.

Blood samples will be taken to measure eosinophil levels, check for antibodies against the study medication, and measure the amount of study medication in your blood.

Lung function tests will be performed before and after receiving a bronchodilator medication at Week 24 and Week 48. These tests measure FEV1, which is the amount of air you can forcefully exhale in one second, and FVC, which is the total amount of air you can exhale.

FeNO measurements will be taken at Week 24 and Week 48 to assess airway inflammation.

You will complete the Asthma Control Questionnaire at Week 48 to evaluate how well your asthma is controlled.

You will complete quality of life questionnaires called the Asthma Quality of Life Questionnaire and the European Quality of Life questionnaire at Week 48 to assess how asthma affects your daily life.

Your vital signs, including blood pressure, heart rate, and temperature, will be checked at each visit.

An electrocardiogram, a test that records the electrical activity of your heart, will be performed at certain visits.

Laboratory tests will be conducted on your blood samples to monitor your overall health and safety.

Any worsening of your asthma that requires treatment with oral steroids for at least 3 days, an emergency room visit, or hospitalization will be recorded as an asthma exacerbation.

After completing the 48-week treatment period, you will stop receiving injections of the study medication or placebo.

A final assessment will be performed at Week 48 to evaluate your condition at the end of the treatment period.

After the treatment period ends at Week 48, you will enter a follow-up period that continues until Week 60.

This 12-week follow-up period allows monitoring of your safety and any effects of the study medication after treatment has stopped.

You will attend follow-up visits during this period for safety assessments.

Any adverse events or health changes will continue to be recorded during this time.

The total duration of your participation in the study, from the first visit to the end of follow-up, will be approximately 60 weeks plus the screening period.