Patient description: The patient is a 15-year-old boy with asthma diagnosed a year ago. He presents with shortness of breath, chest tightening and cough. According to his mother, he didn't respond to the usual corticosteroid inhaler. He was admitted to the emergency department with diagnosis of severe asthma exacerbation. He is a candidate for general corticosteroid therapy. Spirometry revealed a forced expiratory volume in the first second (FEV1) of 60% of the predicted. His past medical history is non-significant. His family history is significant for asthma in his mother and his uncle. He used to be treated with combination of inhaled corticosteroids and Zafirlukast.

Clinical trial eligibility criteria: eligible ages (years): 12.0-999.0,  Asthma Key for study Adult and adolescent participants more than or equal to (>=)12 years of age, at the time of signing the informed consent/assent Participants who have a documented physician diagnosis of asthma for >=2 years that meets the National Heart, Lung, and Blood Institute guidelines (NHLBI) or Global Initiative for Asthma (GINA) guidelines Participants receiving either mepolizumab 100 milligrams (mg) or benralizumab 30 mg for >=12 months prior to screening and have a documented benefit to therapy assessed by either: (i) >=50% reduction in exacerbation frequency since initiating treatment, or (ii) >=50% reduction in maintenance OCS use since initiating treatment, or (iii) No exacerbations in the past 6 months whilst receiving anti-IL-5/5R therapy and an Asthma Control Questionnaire (ACQ)-5 score of less than or equal to (<=)1.5 at screening A well-documented requirement for regular treatment with medium to high dose ICS in the 12 months prior to Visit 1 with or without maintenance OCS. The maintenance ICS dose must be >=440 micrograms (mcg) fluticasone propionate (FP) hydrofluoroalkane (HFA) product daily, or clinically comparable. Participants who are treated with medium dose ICS will also need to be treated with a LABA to qualify for inclusion Current treatment with at least one additional controller medication, besides ICS [for example (e.g.), LABA, LAMA, leukotriene receptor antagonist (LTRA), or theophylline]. Key  for study Participants with presence of a known pre-existing, clinically important lung condition other than asthma. This includes (but is not limited to) current infection, bronchiectasis, pulmonary fibrosis, bronchopulmonary aspergillosis, or diagnoses of emphysema or chronic bronchitis (chronic obstructive pulmonary disease other than asthma) or a history of lung cancer Participants with other conditions that could lead to elevated eosinophils such as hyper-eosinophilic syndromes including (but not limited to) Eosinophilic Granulomatosis with Polyangiitis (EGPA, formerly known as Churg-Strauss Syndrome) or Eosinophilic Esophagitis A current malignancy or previous history of cancer in remission for less than 12 months prior to screening (Participants that had localized carcinoma of the skin which was resected for cure will not be excluded) Cirrhosis or current unstable liver or biliary disease per investigator assessment defined by the presence of ascites, encephalopathy, coagulopathy, hypoalbuminemia, esophageal or gastric varices, persistent jaundice Participants with current diagnosis of vasculitis. Participants with high clinical suspicion of vasculitis at screening will be evaluated and current vasculitis excluded prior to enrolment Participants who have received Omalizumab (Xolair), dupilumab (Dupixent) or reslizumab (Cinqair/Cinqaero) within 130 days prior to Visit 1 Participants who have received any Monoclonal antibody (mAb) within 5 half-lives of Visit 1 Corrected QT interval using Fridericia's formula (QTcF) >=450 milliseconds (msec) or QTcF >=480 msec for participants with Bundle Branch Block at screening Visit 1 Current smokers or former smokers with a smoking history of >=10 pack years (number of pack years equal to [number of cigarettes per day/20] times number of years smoked). A former smoker is defined as a participant who quit smoking at least 6 months prior to Visit 1