Percentage of participants who required urgent healthcare visit for treatment of acute asthma exacerbation were reported. As per protocol, asthma exacerbation (relapse/de novo) was defined as either 1) increase of asthma symptoms (cough, wheeze, chest tightness, and/or shortness of breath) that did not resolve within 2 hours after use of rescue albuterol or corticosteroids and required an unscheduled medical visit or 2) during scheduled study visit, participant had acute worsening of asthma symptoms and a reduction of greater than or equal to (>=) 20 percent (%) in Peak Expiratory Flow (PEF) or Forced Expiratory Volume in 1 Second (FEV1), which in the opinion of the investigator required treatment with systemic corticosteroids. Asthma exacerbations were analyzed in a non-adjudicated manner (by investigator), which were then adjudicated in a blinded fashion by the sponsor medical monitor prior to database lock to determine whether the reported exacerbation met the protocol definition.

Evaluable population included all participants who received any study drug and were followed according to the protocol through Day 42.

An adverse event (AE) was any untoward medical occurrence attributed to study drug in a participant who received study drug. A serious adverse event (SAE) was an AE resulting in any of the following outcomes or deemed significant for any other reason: death; initial or prolonged inpatient hospitalization; life-threatening experience (immediate risk of dying); persistent or significant disability/incapacity; congenital anomaly. Treatment-emergent are events between administration of study drug and Day 84 that were absent before treatment or that worsened relative to pretreatment state.

Safety population included all participants who received any study drug.

Percentage of participants who required an urgent healthcare visit for treatment of an acute asthma exacerbation were reported. As per protocol, asthma exacerbation (relapse or de novo) was defined as either 1) an increase of asthma symptoms (cough, wheeze, chest tightness, and/or shortness of breath) that did not resolve within 2 hours after the use of rescue albuterol or corticosteroids and required an unscheduled medical visit or 2) during a scheduled study visit, the participant had acute worsening of asthma symptoms and a reduction of >=20% in PEF or FEV1, which in the opinion of the investigator required treatment with systemic corticosteroids. Asthma exacerbations were analyzed in a non-adjudicated manner (by investigator), which were then adjudicated in a blinded fashion by the sponsor medical monitor prior to database lock to determine whether the reported exacerbation met the protocol definition.

Evaluable population included all participants who received any study drug and were followed according to the protocol through Day 42.

Asthma Control Questionnaire (ACQ) is a participant-reported questionnaire to assess the asthma control with 6 items assessing night-time waking, symptoms on waking, activity limitation, shortness of breath, wheeze, and rescue short-acting beta agonist use. Each item was rated on a 7-point Likert scale ranging from 0 (no impairment) to 6 (maximum impairment). Overall ACQ score is the mean of the 6 item scores with a score range of 0 (well controlled) to 6 (extremely poor controlled). Results were reported for overall ACQ score and 6 item scores.

Evaluable population included all participants who received any study drug and were followed according to the protocol through Day 42. Here, "Number Analyzed" signified those participants who were evaluable for this outcome measure at specified time points.

The FEV1 is the maximal volume of air exhaled in the first second of a forced expiration from a position of full inspiration. Spirometry was performed with the participant in the sitting position at study sites by the investigator or qualified designee according to American Thoracic Society (ATS)/European Respiratory Society (ERS) guidelines. Multiple forced expiratory efforts (at least 2 but no more than 5) were performed for each office spirometry session and the 2 best efforts that met ATS/ERS acceptability and reproducibility criteria were recorded. The best efforts were based on the highest FEV1. The maximum FEV1 of the 2 best efforts was used for the analysis.

Evaluable population included all participants who received any study drug and were followed according to the protocol through Day 42. Here, "Number Analyzed" signified those participants who were evaluable for this outcome measure at specified time points.

The FEV1 is the maximal volume of air exhaled in the first second of a forced expiration from a position of full inspiration. Home peak flow testing for FEV1 was performed every morning while sitting or standing prior to using any medication (if needed) for asthma. Mean FEV1 values for each week were reported starting from Day 1 to Day 84.

Evaluable population included all participants who received any study drug and were followed according to the protocol through Day 42. Here, "Number Analyzed" signified those participants who were evaluable for this outcome measure at specified time points.

The PEF is a participant's maximum speed of expiration, as measured with a peak flow meter. Home peak flow testing for PEF was performed every morning while sitting or standing prior to using any medication (if needed) for asthma. Mean PEF values for each week were reported starting from Day 1 to Day 84.

Evaluable population included all participants who received any study drug and were followed according to the protocol through Day 42. Here, "Number Analyzed" signified those participants who were evaluable for this outcome measure at specified time points.

Rescue beta-2 agonist use (total number of puffs for the prior day) was collected daily in the morning by the participants in the electronic daily diary provided to them. Participants were instructed not to collect rescue beta-2 agonist used prior to exercise. Average values for each week were reported starting from Day 1 to Day 84.

Evaluable population included all participants who received any study drug and were followed according to the protocol through Day 42. Here, "Number Analyzed" signified those participants who were evaluable for this outcome measure at specified time points.

Physician Global Assessment (PGA) consisted of a single physician-rated question assessing participant's status as 'excellent', 'good', 'moderate', 'poor', 'worsening' or 'not applicable (NA)'. Number of participants were categorically summarized.

Evaluable population included participants who received any study drug and were followed according to the protocol through Day 42. Here, "Number Analyzed" signified those participants who were evaluable for this outcome measure at specified time points.

Asthma Quality of Life Questionnaire (Standardized Version) (AQLQ[S]): a 32-item questionnaire that measures the functional impairments experienced by adult participants including 4 domains (symptoms, activity limitations, emotional function, and environmental stimuli). Participants were asked to recall their experiences during the previous 2 weeks and to score each of the 32 questions on a 7-point scale ranging from 7 (no impairment) to 1 (severe impairment). The overall score was calculated as the mean response to all questions. The 4 domain scores were the means of the responses to the questions in each of the domains. Overall AQLQ score and 4 domain scores ranged from 7 (no impairment) to 1 (severe impairment).

Evaluable population included participants who received any study drug and were followed according to the protocol through Day 42. Here, "Number Analyzed" signified those participants who were evaluable for this outcome measure at specified time points.

Healthcare resource use was summarized by resource type from information on asthma exacerbations, and asthma related medications. Healthcare resource utilization assessed the total number of hospitalizations, urgent care, primary care clinic visits, asthma specialist clinic visits, telephone calls, and home management.

Evaluable population included all participants who received any study drug and were followed according to the protocol through Day 42.

The Cmax of benralizumab is reported. Non-compartmental pharmacokinetic (PK) analysis was used for evaluation.

Safety population included all participants who received any study drug. Only participants in benralizumab arms were included in pharmacokinetic evaluation. Only those participants who had PK values above the quantification limit were analyzed for this outcome measure.

AUClast = area under the concentration-time curve from time 0 to last measurable concentration. Non-compartmental PK analysis was used for evaluation.

Safety population included all participants who received any study drug. Only participants in benralizumab arms were included in pharmacokinetic evaluation. Only those participants who had PK values above the quantification limit were analyzed for this outcome measure.

AUC [0 - infinity] = Area under the serum concentration versus time curve (AUC) from time zero (pre-dose) to extrapolated infinite time (0 - infinity). It is obtained from AUC (0 - t) plus AUC (t - infinity). Non-compartmental PK analysis was used for evaluation.

Safety population included all participants who received any study drug. Only participants in benralizumab arms were included in pharmacokinetic evaluation. Only those participants who had PK values above the quantification limit were analyzed for this outcome measure.

Systemic clearance of a drug is a measure of the rate at which a drug is metabolized or eliminated by normal biological processes. Non-compartmental PK analysis was used for evaluation. Clearance was normalized to participant's body weight.

Safety population included all participants who received any study drug. Only participants in benralizumab arms were included in pharmacokinetic evaluation. Only those participants who had PK values above the quantification limit were analyzed for this outcome measure.

Terminal phase elimination half-life is the time measured for the serum concentration to decrease by one half. Non-compartmental PK analysis was used for evaluation.

Safety population included all participants who received any study drug. Only participants in benralizumab arms were included in pharmacokinetic evaluation. Only those participants who had PK values above the quantification limit were analyzed for this outcome measure.

Volume of distribution is defined as the theoretical volume in which the total amount of drug would need to be uniformly distributed to produce the desired serum concentration of a drug. Vc = volume of distribution of the central compartment, calculated as Dose/Cmax; where Cmax = maximum observed serum concentration. Non-compartmental PK analysis was used for evaluation. Results were normalized to participant's body weight.

Safety population included all participants who received any study drug. Only participants in benralizumab arms were included in pharmacokinetic evaluation. Only those participants who had PK values above the quantification limit were analyzed for this outcome measure.

Volume of distribution is defined as the theoretical volume in which the total amount of drug would need to be uniformly distributed to produce the desired serum concentration of a drug. Vss = steady state volume of distribution, calculated as MRT*CL, where MRT is the Mean Residence Time and CL is systemic clearance; which is a measure of the rate at which a drug is metabolized or eliminated by normal biological processes. Non-compartmental PK analysis was used for evaluation. Results were normalized to participant's body weight.

Safety population included all participants who received any study drug. Only participants in benralizumab arms were included in pharmacokinetic evaluation. Only those participants who had PK values above the quantification limit were analyzed for this outcome measure.

Number of participants with anti-drug antibodies to benralizumab is reported.

Safety population included all participants who received any study drug. Only participants from benralizumab arms were included in immunogenicity evaluation. Only participants with adequate sample were evaluable for this outcome measure.