Trial Outcomes & Findings for Effectiveness and Safety Study of Tezepelumab in Adults & Adolescent Participants With Severe Asthma in the United States (NCT NCT05329194)

The study was conducted from 29 April 2022 (first participant first visit) to 01 October 2025 (last participant last visit) at 32 study sites in the United States of America (USA).

Participants who met the inclusion criteria and none of the exclusion criteria were enrolled to the study. All study assessments were performed as per the schedule of activities.

Effectiveness and Safety Study of Tezepelumab in Adults & Adolescent Participants With Severe Asthma in the United States

Asthma exacerbations were defined by worsening of asthma symptoms that leads to temporary bolus/burst of systemic corticosteroids for at least 3 consecutive days, or an emergency department (ED) or urgent care visit due to asthma that required systemic corticosteroid (SCS), and/or inpatient hospitalization (≥24 hours) due to asthma. The AAER was based on exacerbations reported by the investigator over 52 weeks. The exacerbation rate was compared between the 12-month period before \[baseline period (BP)\] and the 12-month period after initiation of tezepelumab \[up to study Week 52 (Visit 15) = study period (SP)\].

The number of participants with at least one asthma exacerbation in the 12-month period before (baseline period) and after initiation of tezepelumab (study period) (up to study Week 52 = study period) were assessed.

The number of participants who completed the 52 -week study period following tezepelumab initiation with at least 50% reduction, and 100% reduction in total number of asthma exacerbations were assessed.

The cumulative asthma exacerbation days over 52 weeks before (baseline period) and after initiation of tezepelumab (study period) was assessed.

The time to first exacerbation after initiation of tezepelumab was assessed. Data for median time to event have been presented for this endpoint. The median is the descriptive statistics median calculated using a subset of Participants with an event.

The rate of asthma exacerbations associated with hospitalization over 52 weeks before (baseline period) and after initiation of tezepelumab (study period) was assessed.

The rate of asthma exacerbations associated with ED/UC visits over 52 weeks before (baseline period) and after initiation of tezepelumab (study period) was assessed.

The rate of asthma exacerbations associated with hospitalizations or ED/UC visits over 52 weeks before (baseline period) and after initiation of tezepelumab (study period) was assessed.

The number of participants with asthma exacerbations associated with hospitalizations or ED/UC visits in in the 12-month periods before (baseline period) and after initiation of tezepelumab (study period) (up to study Week 52 = study period) were assessed.

The cumulative asthma exacerbation days associated with hospitalizations or ED/UC over 52 weeks before (baseline period) and after initiation of tezepelumab (study period) were assessed. Total days of exacerbations resulting in hospitalizations or ED/UC visits have been presented.

Lung function (FEV1) was measured pre-bronchodilator (pre-BD) by spirometry test. FEV1 is defined as the volume of air exhaled from the lungs in the first second of a forced expiration.

Change from baseline in pre-bronchodilator FEV1 was assessed after initiation of tezepelumab. FEV1 is defined as the volume of air exhaled from the lungs in the first second of a forced expiration.

Number of pre-BD FEV1 responders was defined as participants who achieved either at least 5% or 100 mL improvement from baseline.

The Asthma Control Questionnaire-6 (ACQ-6) is a shortened version of the ACQ that assesses the adequacy of asthma control and change in asthma control which occurs spontaneously or as a result of treatment. ACQ assesses symptoms and rescue bronchodilator use. Questions are weighted equally and scored from 0 (totally controlled) to 6 (severely uncontrolled), with higher scores indicating worse asthma control. The mean (average) ACQ-6 score is the mean of the responses.

The Asthma Impairment and Risk Questionnaire (AIRQ) is a Patient Reported Outcome (PRO) tool intended to identify participants 12 years and older whose health may be at risk because of uncontrolled asthma. It has 10 questions that ask about respiratory symptoms, activity limitation, sleep, rescue medication use, social activities, exercise, difficulty controlling asthma, and exacerbations. All items have a yes/no response option and the tool is scored by summing the total number of 'yes' responses. This sum score is used to assess level of asthma control, ranging from 0 to 10, with higher scores indicating worse asthma control, where: 0-1 is well controlled, 2-4 is not well controlled, and 5-10 is very poorly controlled.

St. George's Respiratory Questionnaire (SGRQ) is a 50-item Patient Reported Outcome (PRO) instrument used to measure health status of participants with airway obstruction diseases. Questionnaire has 2 parts: part 1 consists of 8 items pertaining to severity of respiratory symptoms in preceding 4 weeks; part 2 consists of 42 items related to daily activity and psychosocial impacts of individual's respiratory condition. SGRQ yields a total score and 3 components scores (symptoms, activity, and impacts). Total score indicates impact of disease on overall health status, and it is expressed as percentage of overall impairment, in which 100 represents worst possible health status and 0 indicates best possible health status. Likewise, domain scores range from 0 to 100, with higher scores indicative of greater impairment.

Change from baseline in Asthma Control Questionnaire-6 (ACQ-6) score was assessed. The ACQ-6 is a shortened version of the ACQ that assesses the adequacy of asthma control and change in asthma control which occurs spontaneously or as a result of treatment. ACQ assesses symptoms and rescue bronchodilator use. Questions are weighted equally and scored from 0 (totally controlled) to 6 (severely uncontrolled), with higher scores indicating worse asthma control.

Change from baseline in Asthma Impairment and Risk Questionnaire (AIRQ) score was assessed. AIRQ is a Patient Reported Outcome (PRO) tool intended to identify participants 12 years and older whose health may be at risk because of uncontrolled asthma. It has 10 questions that ask about respiratory symptoms, activity limitation, sleep, rescue medication use, social activities, exercise, difficulty controlling asthma, and exacerbations. All items have a yes/no response option and the tool is scored by summing the total number of 'yes' responses. This sum score is used to assess level of asthma control, ranging from 0 to 10, with higher scores indicating worse asthma control, where: 0-1 is well controlled, 2-4 is not well controlled, and 5-10 is very poorly controlled.

Change from baseline in St. George's Respiratory Questionnaire (SGRQ) score was assessed. SGRQ is a 50-item Patient Reported Outcome (PRO) instrument used to measure health status of participants with airway obstruction diseases. Questionnaire has 2 parts: part 1 consists of 8 items pertaining to severity of respiratory symptoms in preceding 4 weeks; part 2 consists of 42 items related to daily activity and psychosocial impacts of individual's respiratory condition. SGRQ yields a total score and 3 components scores (symptoms, activity, and impacts). Total score indicates impact of disease on overall health status, and it is expressed as percentage of overall impairment, in which 100 represents worst possible health status and 0 indicates best possible health status. Likewise, domain scores range from 0 to 100, with higher scores indicative of greater impairment.

Number of ACQ-6 responders were assessed. Individual changes from baseline of ≥ 0.5 were considered to be clinically meaningful (minimum clinically important difference \[MCID\]). ACQ-6 responders in this study were defined as participants who achieved ≥ 1 MCID.

Number of AIRQ responders were assessed. Individual changes from baseline of ≥ 2 were considered to be clinically meaningful (MCID). AIRQ responders in this study were defined as participants who achieved ≥ 1 MCID.

Number of SGRQ responders were assessed. Individual changes from baseline of ≥ 4 were considered to be clinically meaningful (MCID). SGRQ (total and component score) responders in this study were defined as participants who achieved ≥ 1 MCID.

Number of participants who require any SCS use in the 12-month periods before (baseline period) and after initiation of tezepelumab (up to study Week 52 = study period) were assessed.

Cumulative annualized SCS dose in the 12-month periods before (baseline period) and after initiation of tezepelumab (up to study Week 52 = study period) were assessed. Cumulative annualized SCS dose for each participant was calculated as followed: Cumulative annualized SCS dose = \[sum of (cumulative SCS dose)/length of the planned treatment period\]\*365.25

Number of participants who require longer-term (\>30 consecutive days) SCS use in the 12-month periods before (baseline period) and after initiation of tezepelumab (up to study Week 52 = study period) were assessed.

Number of participants with specific type of asthma-related HRU in the 12-month period before (baseline period) and after initiation of tezepelumab (up to study Week 52 = study period) were assessed.

Duration of asthma-related hospitalization in the 12-month period before (baseline period) and after initiation of tezepelumab (up to study Week 52 = study period) was assessed.

AAER based on asthma exacerbations in the 12-month period before \[baseline period (BP)\] and after initiation of tezepelumab \[up to study Week 52 = study period (SP)\] was assessed in following subgroups of participants: Blood eosinophil count (BEC) ≥300 cells/microliter; BEC \<300 cells/microliter; With clinically-relevant allergy to perennial aeroallergen; Without clinically-relevant allergy to a perennial aeroallergen; Participants who identify as Black/African American; Adolescents (12-17 years); Comorbid diagnosis of mild to moderate chronic obstructive pulmonary disease (COPD); Significant smoking history (≥10 pack-years of smoking).

The number of participants with at least one asthma exacerbations in the 12-month period before \[baseline period (BP)\] and after initiation of tezepelumab \[up to study Week 52 = study period (SP)\] were assessed in the following subgroups of participants: BEC ≥300 cells/microliter; BEC \<300 cells/microliter; With a clinically-relevant allergy to a perennial aeroallergen; Without a clinically-relevant allergy to a perennial aeroallergen; Participants who identify as Black/African American; Adolescents (12-17 years); Comorbid diagnosis of mild to moderate COPD; Significant smoking history (≥10 pack-years of smoking).

The number of participants who completed the 52-week study period following tezepelumab initiation with at least 50% reduction, and 100% reduction in total number of asthma exacerbations were assessed in the following subgroups of participants: BEC ≥300 cells/microliter; BEC \<300 cells/microliter; With a clinically-relevant allergy to a perennial aeroallergen; Without a clinically-relevant allergy to a perennial aeroallergen; Participants who identify as Black/African American; Adolescents (12-17 years); Comorbid diagnosis of mild to moderate COPD; Significant smoking history (≥10 pack-years of smoking).

The cumulative asthma exacerbation days over 52 weeks before \[baseline period (BP)\] and after initiation of tezepelumab \[study period (SP)\] were assessed in the following subgroups of participants: BEC ≥300 cells/microliter; BEC \<300 cells/microliter; With a clinically-relevant allergy to a perennial aeroallergen; Without a clinically-relevant allergy to a perennial aeroallergen; Participants who identify as Black/African American; Adolescents (12-17 years); Comorbid diagnosis of mild to moderate COPD; Significant smoking history (≥10 pack-years of smoking).

Rate of asthma exacerbations associated with hospitalization over 52 weeks before \[baseline period (BP)\] and after initiation of tezepelumab \[study period (SP)\] was assessed in the following subgroups of participants: BEC ≥300 cells/µL; BEC \<300 cells/µL; With a clinically-relevant allergy to perennial aeroallergen; Without a clinically-relevant allergy to perennial aeroallergen; Participants who identify as Black/African American; Adolescents (12-17 years); Comorbid diagnosis of mild to moderate COPD; Significant smoking history (≥10 pack-years of smoking).

Rate of asthma exacerbations associated with ED/UC visits over 52 weeks before \[baseline period (BP)\] and after initiation of tezepelumab \[study period (SP)\] was assessed in following subgroups of participants: BEC ≥300 cells/µL; BEC \<300 cells/µL; With a clinically-relevant allergy to perennial aeroallergen; Without a clinically-relevant allergy to perennial aeroallergen; Participants who identify as Black/African American; Adolescents (12-17 years); Comorbid diagnosis of mild to moderate COPD; Significant smoking history (≥10 pack-years of smoking).

Rate of asthma exacerbations associated with hospitalizations or ED/UC visits over 52 weeks before \[baseline period (BP)\] and after initiation of tezepelumab \[study period (SP)\] was assessed in following subgroups of participants: BEC ≥300 cells/µL; BEC \<300 cells/µL; With clinically-relevant allergy to perennial aeroallergen; Without clinically-relevant allergy to perennial aeroallergen; Participants who identify as Black/African American; Adolescents (12-17 years); Comorbid diagnosis of mild to moderate COPD; Significant smoking history (≥10 pack-years of smoking).

Number of participants with specific type of asthma related HRU in the 12-month period before \[baseline period (BP)\] and after initiation of tezepelumab \[up to study Week 52 = study period (SP)\] were assessed in the following subgroups of participants: BEC ≥300 cells/microliter; BEC \<300 cells/microliter; With a clinically-relevant allergy to a perennial aeroallergen; Without a clinically-relevant allergy to a perennial aeroallergen; Participants who identify as Black/African American; Adolescents (12-17 years); Comorbid diagnosis of mild to moderate COPD; Significant smoking history (≥10 pack-years of smoking). FEIA = Fluorescent enzyme immunoassay

Duration of asthma-related hospitalization in 12-month period before \[baseline period (BP)\] and after initiation of tezepelumab \[up to study Week 52 = study period (SP)\] was assessed in following subgroups of participants: BEC≥300 cells/µL; BEC\<300 cells/µL; With clinically-relevant allergy to perennial aeroallergen; Without clinically-relevant allergy to perennial aeroallergen; Participants who identify as Black/African American; Adolescents (12-17 years); Comorbid diagnosis of mild to moderate COPD; Significant smoking history (≥10 pack-years of smoking).

The safety and tolerability of tezepelumab were assessed. Data for adverse events on-treatment period have been presented.