Comparing Treatment Efficacy With Mepolizumab and Omalizumab in Severe Asthma - "Choosebetweenamab".

Inclusion Criteria

• •Participants must have a duration of asthma of greater than one year.
• •They must have confirmed asthma defined as: (i) forced expiratory volume (FEV1) reversibility greater than or equal to 12%, and greater than or equal to 200 mL at baseline within 30 minutes after administration of salbutamol (200 to 400 micrograms), or (ii) airway hyperresponsiveness defined as a greater than 20% decline in FEV1 during a direct bronchial provocation test or greater than 15% decline during an indirect bronchial provocation test, or (iii) peak expiratory flow (PEF) variability of greater than 15% between the two highest and two lowest peak expiratory flow rates during 14 days.
• •They must have evidence of poor asthma control despite optimal ICS and long acting beta agonist (LABA), be treated by a respiratory physician or immunologist, and have demonstrated acceptable adherence and inhaler technique. Poor control is defined as: evidence of an FEV1 \<80% of predicted in the last year on at least one occasion; treatment with OCS, either daily for at least 6 weeks, or a cumulative dose of OCS of at least 500 mg prednisolone equivalent in the previous 12 months, unless contraindicated or not tolerated.
• •In addition they must demonstrate an: (a) an Asthma Control Questionnaire (ACQ-5)38 score of at least 2.0, as assessed in the previous month, and (b) while receiving optimised asthma therapy in the past 12 months, experienced at least 1 admission to hospital for a severe asthma exacerbation, or 1 severe asthma exacerbation, requiring documented use of OCS initiated or increased for at least 3 days, or parenteral corticosteroids prescribed/supervised by a physician.
• •They must also demonstrate evidence of a dual allergic/ eosinophilic phenotype. This is defined as: a total serum IgE \>30IU/mL, past or current evidence of atopy documented by skin prick testing or radioallergosorbent assay, and the participant must have a blood eosinophil count greater than or equal to 300 cells per microlitre in the last 6 weeks.
• •Unable to attend appointments
• •Significant psychiatric illness