Worst-Itch numerical rating score (WI-NRS) is a patient report outcome (PRO) comprised of a single item rated on a scale from 0 ("No itch") to 10 ("Worst imaginable itch").

Concentration of dupilumab in serum over time

Annualized rate of severe asthma exacerbations during the 52-week treatment period.

Incidence of TEAEs, SAEs, AESIs, and AEs leading to permanent treatment discontinuation.

The NPS was the sum of the right and left nostril scores and assessed by central video recordings of bilateral nasal endoscopy. For each nostril, NPS was graded based on polyp size which ranged from 0: no polyps, 1: small polyps in the middle meatus not reaching below the inferior border of the middle turbinate, 2: polyps reaching below the lower border of the middle turbinate, 3: large polyps reaching the lower border of the inferior turbinate or polyps medial to the middle turbinate, 4: large polyps causing complete obstruction of the inferior nasal cavity. Total NPS was the sum of right and left nostril scores; ranged from 0 (no polyps) to 8 (large polyps). Higher scores indicated more severe disease. Baseline was defined as the last available value before randomization.

Blood samples were collected at specified timepoints to obtain dupilumab concentration.

WI-NRS is a patient reported outcome (PRO) comprised of a single item rated on a scale from 0 ("No itch") to 10 ("Worst imaginable itch").

WI-NRS is a PRO comprised of a single item rated on a scale from 0 ("No itch") to 10 ("Worst imaginable itch").

For patients that can undergo a methacholine challenge, one doubling dose improvement in PC20 methacholine. For those that cannot undergo a methacholine challenge a 50% reduction in FEV1 reversibility.

The IGA is an assessment instrument used to rate the severity of AD globally based on a 5-point scale ranging from (0 = clear; 1 = almost clear; 2 = mild; 3 = moderate; 4 = severe), higher score indicated higher severity.

An adverse event (AE) was any untoward medical occurrence in a participant or clinical investigation participant administered a pharmaceutical product and which did not necessarily have to have a causal relationship with this treatment. TEAEs were AEs that developed or worsened or became serious during the TEAE period.

FEV1 was the volume of air (in liters) exhaled from the lungs in the first second of a forced expiration as measured by spirometer. Spirometry was performed after a wash out period of bronchodilators according to their action duration. Baseline was defined as the last available measurement prior to the first study treatment dose if the participant was treated, or the last available value up to enrollment if the participant was not exposed to study treatment in the current study.

A severe asthma exacerbation event was defined as a deterioration of asthma during the 52-week treatment period requiring: use of systemic corticosteroids for \>=3 days; and/or hospitalization or emergency room visit because of asthma requiring systemic corticosteroid treatment. Annualized event rate was defined as the total number of severe exacerbation events that occurred during the 52-week treatment period divided by the total number of participant-years followed in the 52-week treatment period.

A severe asthma exacerbation event was defined as a deterioration of asthma during the 52-week treatment period requiring: use of systemic corticosteroids for \>=3 days; and/or hospitalization or emergency room visit because of asthma requiring systemic corticosteroid treatment. Annualized event rate was defined as the total number of severe exacerbation events that occurred during the 52-week treatment period divided by the total number of participant-years followed in the 52-week treatment period.

Percentage reduction of OCS dose was calculated as (optimized OCS dose \[mg/day\] at baseline - final OCS dose at Week 24)/optimized OCS dose at baseline x 100. Result is presented as Least Squares Mean (Standard Error) percentage reduction from baseline derived from ANCOVA model with missing data multiply imputed.

The Primary Outcome Measure (Percentage Reduction From Baseline in Oral Corticosteroids Dose at Week 24 While Maintaining Asthma Control) is summarized above, as LS Mean (SE). Table below provides a supplementary presentation of the Primary Outcome Measure data; result is presented as median (inter-quartile range). Percentage reduction of OCS dose was calculated as (optimized OCS dose \[mg/day\] at baseline - final OCS dose at Week 24)/optimized OCS dose at baseline x 100.

A severe exacerbation was defined as a deterioration of asthma requiring: use of systemic corticosteroids for \>=3 days; or hospitalization or emergency room visit because of asthma, requiring systemic corticosteroids. Annualized event rate was the total number of exacerbations that occurred during the treatment period divided by the total number of participant-years treated.

FEV1 was the volume of air exhaled in the first second of a forced expiration as measured by spirometer.

An Adverse Event (AE) was any untoward medical occurrence in a participant or clinical investigation participant administered a pharmaceutical product and which did not necessarily had to have causal relationship with treatment. TEAEs were defined as AEs that developed, worsened, or became serious during the treatment emergent AE period (time from first dose of investigational medicinal product \[IMP\] in LTS12551 up to the last dose of dupilumab plus 14 weeks). A Serious AE (SAE) was any untoward medical occurrence that at any dose: resulted in death, was life-threatening, required inpatient hospitalization or prolongation of existing hospitalization, resulted in persistent or significant disability/incapacity, was a congenital anomaly/birth defect, was a medically important event.

Clinical response by modified Mayo score is defined as a decrease from baseline in the modified Mayo score of ≥2 points and at least a 30% reduction from baseline, and a decrease in rectal bleeding subscore of ≥1 OR an absolute rectal bleeding subscore of 0 or 1. The modified Mayo score consists of 3 subscores; a patient-reported subscore for rectal bleeding, a patient-reported subscore for stool frequency, and a Mayo endoscopic subscore. Each subscore ranges 0-3 with higher scores indicating greater disease severity. The total modified Mayo score ranges 0-9 with higher scores indicating greater disease severity.

NPS was the sum of the right and left nostril scores, as evaluated by means of nasal endoscopy. Total score ranges from 0 to 8 (scored 0 \[no polyp\] to 4 \[large polyps\] for each nostril), with a lower score indicating smaller-sized polyps.

FEV1 was the volume of air exhaled in the first second of a forced expiration as measured by spirometer.

FEV1 was the volume of air exhaled in the first second of a forced expiration as measured by spirometer.

An asthma exacerbation was defined as the occurrence of any of the following: ≥30% reduction from baseline in morning PEF on 2 consecutive days; or ≥6 additional reliever puffs of albuterol or levalbuterol in a 24-hour period (compared to baseline) on 2 consecutive days; or deterioration of asthma, as determined by the investigator, requiring systemic steroid treatment, or an increase in inhaled corticosteroid (ICS) of ≥4 times the last dose received prior to discontinuation from the study, or hospitalization. The occurrence of asthma exacerbations by individual criteria are reported.