Study to Evaluate Tezepelumab in Adults & Adolescents With Severe Uncontrolled Asthma

The annual exacerbation rate is based on unadjudicated exacerbations reported by the investigator in the eCRF. The analysis is based on the primary population (Full Analysis Set)

The annual exacerbation rate is based on unadjudicated exacerbations reported by the investigator in the eCRF. This analysis is based on subjects with baseline eosinophils < 300 cells/uL

Mean change from baseline in FEV1 as compared to placebo at Week 52. FEV1 is defined as the volume of air exhaled from the lungs in the first second of a forced expiration.

Mean change from baseline in AQLQ(S)+12 as compared to placebo at Week 52. The AQLQ(S)+12 is a questionnaire that measures the health-related quality of life experienced by asthma subjects. The total score is defined as the average of all 32 questions in the AQLQ(S)+12 questionnaire. AQLQ(S)+12 is a 7-point scale questionnaire, ranging from 7 (no impairment) to 1 (severe impairment).

Change from baseline in ACQ-6 as compared to placebo at Week 52. The ACQ-6 captures asthma symptoms and short-acting β2-agonist use via subject-report. Questions are weighted equally and scored from 0 (totally controlled) to 6 (severely uncontrolled). The ACQ-6 score is the mean of the responses.

Mean change from baseline at Week 52 in Asthma Symptom Diary. The Asthma Symptom Diary comprises of 10 items (5 items in the morning; 5 items in the evening). Asthma symptoms during night time and daytime are recorded by the patient each morning and evening in the daily diary. A daily ASD score is the mean of the 10 items. Responses for all 10 items are required to calculate the daily ASD score; otherwise, it is treated as missing. For the 7-day average asthma symptom score, scoring is done with no imputation using the mean of at least 4 of the 7 daily ASD scores as a mean weekly item score. The 7-day average ASD score ranges from 0 to 4, where 0 indicates no asthma symptoms.

Time to first occurrence of asthma exacerbation post-randomisation, presented as number of subjects with at least one asthma exacerbation as reported by the investigator in the eCRF.

Mean change from baseline at Study Week 52 in FeNO (ppb) measured at site

Daily rescue medication use is defined as: Number of night inhaler puffs + 2 x [number of night nebulizer times] + number of daytime inhaler puffs + 2 x [number of day nebulizer times]. Weekly means are calculated using at least 4 of 7 days of daily rescue medication use.

WPAI+CIQ (Work Productivity and Activity Impairment plus Classroom Impairment Questionnaire) contains 10 questions. Work productivity loss is derived by sum of percentage of missed work due to asthma and product of percentage of actual working hours times degree of asthma affecting work productivity while working. Percentage of missed work due to asthma is calculated by number of hours missed work due to asthma divided by total number of hours missed work plus number of hours actually worked.

WPAI+CIQ (Work Productivity and Activity Impairment plus Classroom Impairment Questionnaire) contains 10 questions. Class productivity loss is derived by sum of percentage of missed class hours due to asthma and product of percentage of actual hours in class times degree of asthma affecting productivity while in class. Percentage of missed hours in class due to asthma is calculated by number of hours in class missed due to asthma divided by total number of hours in class missed plus number of hours actually in class.

WPAI+CIQ (Work Productivity and Activity Impairment plus Classroom Impairment Questionnaire) contains 10 questions. Activity impairment is the degree health affected regular activities (other than work or class) rated from 0 to 10, with 0 meaning no effect, divided by 10, and then expressed as a percentage.

Mean serum trough PK concentrations taken pre-dose at each visit

Mean change from baseline at Study Week 52 in EQ-5D-5L VAS. EQ-5D-5L visual analogue scale (VAS) allows subjects to rate current health status on a scale of 0-100, with 0 being the worst imaginable health state.

CGIC (Clinical global impression of change) is an overall evaluation of response to treatment, conducted by investigator using 7-point rating scale, ranging from 1 (very much improved), to 7 (very much worse)

PGIC (Patient global impression of change) is an overall evaluation of response to treatment, conducted by the patient using 7-point rating scale, ranging from 1 (very much improved), to 7 (very much worse).

PGI-S (Patient global impression of severity) is an overall evaluation of patient's perception of overall symptom severity using a 6-point rating scale, ranging from 0 = No symptoms, 1=Very mild symptoms, 2=Mild symptoms, 3=Moderate symptoms, 4=Severe symptoms, 5=Very severe symptoms

Mean change from baseline at Study Week 52 in blood eosinophils (cells/uL)

Mean change from baseline at Study Week 52 in total serum IgE (IU/mL)

Number of participants with asthma specific healthcare utilizations (e.g. unscheduled physician visits, unscheduled phone calls to physicians, use of other asthma medications) over 52 weeks

Mean change from baseline in home based morning PEF (L/min) at Study Week 52. Home PEF testing will be performed by the subject in the morning upon awakening and in the evening at bedtime using an electronic, hand-held spirometer. Weekly means are calculated using at least 4 of the 7 days of PEF data.

Mean change from baseline in home based evening PEF (L/min) at Study Week 52. Home PEF testing will be performed by the subject in the morning upon awakening and in the evening at bedtime using an electronic, hand-held spirometer. Weekly means are calculated using at least 4 of the 7 days of PEF data.

Mean change from baseline in night time awakenings due to asthma at Study Week 52. Night-time awakenings percentage defined as number of nights with awakenings due to asthma and requiring rescue medication divided by number of nights with data and multiplied by 100%. At least 4 out of 7 days of data is required to calculate a weekly mean.

Anti-drug antibodies (ADA) responses at baseline and post baseline. Persistently positive is defined as positive at >=2 post baseline assessments (with >=16 weeks between the first and the last positive) or positive at last post baseline assessment. Transiently positive is defined as having at least one post baseline ADA positive assessment and not fulfilling the conditions of persistently positive. Treatment boosted ADA defined as baseline positive ADA that was boosted to a 4 fold or higher level following treatment. Treatment emergent ADA defined as sum of treatment induced ADA and treatment boosted ADA.

The proportion of subjects who have no exacerbations is presented as the percentage of subjects with no exacerbations. This is defined as subjects who meet both the following criteria: (1) completed the 52 week treatment period and (2) did not report an exacerbation during this period.

The annualized exacerbation rate is based on exacerbations reported by the investigator that are associated with an emergency room visit, urgent care visit, or a hospitalization (where urgent care visit was captured as an emergency room visit on the eCRF)

Proportion of subjects with at least one asthma exacerbation associated with emergency room visit or hospitalisation as recorded by the investigator in the CRF. This is presented as percentage of subjects with at least one asthma exacerbation associated with emergency room visit or hospitalisation.

The proportion of subjects with no exacerbations is presented as percentage of subjects who meet both the following criteria: (1) completed the 52 week treatment period and (2) did not report an exacerbation associated with emergency room or hospitalisation during this period.

The annualized exacerbation rate is based on exacerbations reported by the investigator that are associated with hospitalization

The annualized exacerbation rate is based on exacerbations as defined for the primary endpoint, but any hospitalisation and ER visits which are adjudicated to be asthma related are added, and those adjudicated to not be asthma related are removed from analyses.

The annualized exacerbation rate is based on exacerbations associated with hospitalisations or ER visits, where hospitalisation and ER visits adjudicated to be asthma related are added, and those adjudicated to not be asthma related are removed from analyses.