Pharmacokinetics and Pharmacodynamics of Mepolizumab Administered Subcutaneously in Children

An Open-label Study to Characterize the Pharmacokinetics and Pharmacodynamics of Mepolizumab Administered Subcutaneously in Children From 6 to 11 Years of Age With Severe Eosinophilic Asthma

Status

Completed

Phases

Phase 2

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT02377427

Enrollment

Registered

2015-03-03

Start date

2015-08-25

Completion date

2018-01-31

Last updated

2019-12-03

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Asthma

Keywords

pharmacokinetics, pediatric, Mepolizumab, subcutaneous, eosinophilic asthma, pharmacodynamics

Brief summary

Mepolizumab is a humanized immunoglobulin G (IgG1) monoclonal antibody (mAb) that exhibits dose proportional and time-independent pharmacokinetics. The study will be conducted in 2 parts. Part A: it will be pharmacokinetic (PK) and pharmacodynamic (PD) study conducted to support the use of mepolizumab in children aged 6 to 11 years with severe eosinophilic asthma and characterize the PK/PD of mepolizumab 40 milligrams (mg) or 100 mg administered subcutaneously depending on participant body weight. Part B: It is a long-term safety / pharmacodynamic phase in which extended treatment for a further 52 weeks will be offered on an optional basis to those subjects eligible for continued treatment. Participants with bodyweight \<40 kilogram (kg) will be dosed with mepolizumab 40 mg and participants with body weight \>=40 kg will be dosed with mepolizumab 100 mg subcutaneously in upper arm or thigh at Visit 2 (Week 0). Approximately 40 male or female participants aged 6 to 11 years will be screened to achieve approximately 28 eligible participants entering the treatment phase to allow availability of 20 evaluable participants, with a minimum of six participants enrolled in the \<40 kg bodyweight group. The total duration of the study will be 22 weeks and will include a run-in period of 1-2 weeks, a treatment period of 12 weeks and a follow-up phase of 8 weeks. A participant will be considered having completed the study if the participant completes all phases of the study including the follow-up phase (Week 20 \[visit 8\]).

Interventions

DRUGMepolizumab

Mepolizumab is supplied as 100 mg lyophilised cake in sterile vials for subcutaneous administration in upper arm or thigh. The vial will be reconstituted with sterile water for injection prior to individual use.

Study design

Allocation

NON_RANDOMIZED

Intervention model

PARALLEL

Primary purpose

OTHER

Masking

NONE

Eligibility

Sex/Gender

ALL

Age

6 Years to 11 Years

Healthy volunteers

Inclusion criteria

* Between 6 and 11 years of age inclusive, at the time of screening. * Diagnosis of severe asthma, defined by the regional asthma guidelines (i.e., National Institute of Health (NIH), Global Initiative for Asthma (GINA), etc.), for at least 12 months prior to Visit 1. If the participant is naïve to the study site, the participant/guardian must self-report a physician diagnosis of asthma and the investigator must confirm by review of medical history with the participant/guardian. * Eosinophilic airway inflammation that is related to asthma characterized as eosinophilic in nature as indicated by: elevated peripheral blood eosinophil count of \>=300 cells per microliter (cells/μL) demonstrated in the past 12 months OR elevated peripheral blood eosinophil count of \>=150/μL at visit 1. * A well-documented requirement for regular treatment with inhaled corticosteroid (\>200 μg/day fluticasone propionate drug powder inhaler \[DPI\] or equivalent daily) in the 12 months prior to Visit 1 with or without maintenance oral corticosteroids (OCS). The ICS dose should represent medium or high dose in children aged 6-11 years of age \[GINA, 2015\]. * Current treatment with an additional controller medication for at least 3 months or a documented failure in the past 12 months of an additional controller medication for at least 3 successive months. \[e.g., long-acting beta-2-agonist (LABA), leukotriene receptor antagonist (LTRA), or theophylline.\] * Forced expiratory volume in one second (FEV1): Persistent airflow obstruction at either Visit 1 or Visit 2 (FEV1 performed prior to first dose of study medication) as indicated by: A pre-bronchodilator FEV1 \<110% predicted (Quanjer, 2012) OR FEV1: Forced vital capacity (FVC) ratio \<0.8. * Previously confirmed history of two or more exacerbations requiring treatment with systemic corticosteroids (CS) (intramuscular \[IM\], intravenous, or oral), in the 12 months prior to visit 1, despite the use of high-dose inhaled corticosteroids (ICS). For participants receiving maintenance CS, the CS treatment for the exacerbations must have been a two-fold increase or greater in the dose. * No changes in the dose or regimen of baseline ICS and/or additional controller medication during the run-in period. * Male or female: Females of childbearing potential must commit to consistent and correct use of an acceptable method of contraception for the duration of the trial and for 4 months after the last dose of investigational product. A urine pregnancy test is required of girls of childbearing potential. This test will be performed at the initial screening visit (visit 1) and will be performed at each scheduled study visit prior to the administration of investigational product, and during the early withdrawal and follow-up visits. * Parent(s)/guardian able to give written informed consent prior to participation in the study, which will include the ability to comply with the requirements and restrictions listed in the consent form. If applicable, the participant must be able and willing to give assent to take part in the study according to the local requirement. * For Part B: The subject has completed all study assessments up-to and including Visit 8 and received all 3 doses of investigational product (IP) in Part A * For Part B: The Principal Investigator (PI) has performed a benefit/risk assessment and this assessment supports continued therapy with mepolizumab. * The subject's parents (or guardian) have given consent and the subject has given assent for continued treatment

Exclusion criteria

* Participants with any history of life threatening asthma (e.g. requiring intubation), immunosuppressive medications intake or immunodeficiency disorder. * Participants with any medical condition or circumstance making the volunteer unsuitable for participation in the study. * Significant abnormality of rate, interval, conduction or rhythm in the 12-lead electrocardiogram (ECG), determined by the investigator in conjunction with the age and gender of the child at Visit 1. * Alanine aminotransferase (ALT), and bilirubin \>2x upper limit of normal (ULN) (isolated bilirubin \>1.5xULN is acceptable if bilirubin is fractionated and direct bilirubin \<35%) at Visit 1. * Positive Hepatitis B Surface Antigen or positive Hepatitis C antibody at Visit 1. * Parent/guardian has a history of psychiatric disease, intellectual deficiency, substance abuse, or other condition (e.g. inability to read, comprehend and write) which will limit the validity of consent to participate in this study. * Unwillingness or inability of the participant or parent/guardian to follow the procedures outlined in the protocol. * Participant who is mentally or legally incapacitated. * Children who are wards of the state or government. * A participant will not be eligible for this study if he/she is an immediate family member of the participating investigator, sub-investigator, study coordinator, or employee of the participating investigator. * Omalizumab: Participants who have received omalizumab within 130 days of Visit 1. * Other Biologics: Participants who have received any biological (other than omalizumab) to treat inflammatory disease within 5 half-lives of visit 1. * History of sensitivity to any of the study medications, or components thereof or a history of drug or other allergy that, in the opinion of the investigator or Medical Monitor, contraindicates their participation. * Hypersensitivity: Participants with allergy/intolerance to a monoclonal antibody or biologic. * The participant has participated in a clinical trial and has received an investigational product within the following time period prior to the first dosing day in the current study: 30 days, 5 half-lives or twice the duration of the biological effect of the investigational product (whichever is longer).

Design outcomes

Primary

Measure	Time frame	Description
Maximum Plasma Concentration (Cmax) of Mepolizumab for Part A	Pre-dose on Weeks 4 and 8; Weeks 9, 12, 16 and 20 post-dose	PK of mepolizumab was evaluated in participants using Cmax. PK samples were collected at pre-dose on Weeks 4 and 8; and at Weeks 9, 12, 16 and 20 post-dose. Cmax was evaluated by population PK methods and mean and standard error from the final model has been tabulated. Estimates have been presented from the final model centered to mean bodyweights of 27 kg, 50 kg and 70 kg. Note the average bodyweight of 70 kg (mean body weight observed in adults) was not investigated in the study. PK Population included all participants receiving at least one dose of mepolizumab beginning at Visit 2 (Week 0) and having at least one blood sample taken at Visit 3 (Week 4) or thereafter with measurable mepolizumab plasma concentration.
Area Under Concentration Time Curve to Infinity (AUC [0-inf]) of Mepolizumab for Part A	Pre-dose on Weeks 4 and 8; Weeks 9, 12, 16 and 20 post-dose	PK of mepolizumab was evaluated in participants using AUC (0-inf). PK samples were collected at pre-dose on Weeks 4 and 8; and at Weeks 9, 12, 16 and 20 post-dose. AUC (0-inf) was evaluated by population PK methods and mean and standard error from the final model has been tabulated. Estimates have been presented from the final model centered to mean bodyweights of 27 kg, 50 kg and 70 kg. Note the average bodyweight of 70kg (mean body weight observed in adults) was not investigated in the study.
Terminal Phase Elimination Half-life (T1/2) of Mepolizumab During Treatment Period for Part A	Pre-dose on Weeks 4 and 8; Weeks 9, 12, 16 and 20 post-dose	PK of mepolizumab was evaluated in participants using t1/2. PK samples were collected at pre-dose on Weeks 4 and 8; and at Weeks 9, 12, 16 and 20 post-dose. T1/2 was evaluated by population PK methods and mean and standard error from the final model has been tabulated. Estimates have been presented from the final model centered to mean bodyweights of 27 kg, 50 kg and 70 kg. Note the average bodyweight of 70kg (mean body weight observed in adults) was not investigated in the study.
Plasma Apparent Clearance (CL/F) of Mepolizumab in Part A	Pre-dose on Weeks 4 and 8; Weeks 9, 12, 16 and 20 post-dose	PK of mepolizumab was evaluated in participants using CL/F. PK samples were collected at pre-dose on Weeks 4 and 8; and at Weeks 9, 12, 16 and 20 post-dose. CL was evaluated by population PK methods and mean and standard error from the final model has been tabulated. Estimates have been presented from the final model centered to mean bodyweights of 27 kg, 50 kg and 70 kg. Note the average bodyweight of 70kg (mean body weight observed in adults) was not investigated in the study.
Ratio to Baseline in Absolute Blood Eosinophil Count at Week 12 for Part A	Baseline and Week 12	PD of mepolizumab was evaluated in participants using ratio to Baseline in absolute blood eosinophil count. Blood samples were collected at indicated time points. Baseline was defined as the latest value recorded prior to the first dose of mepolizumab. Ratio to Baseline was calculated as post-dose visit value/Baseline value. It was evaluated by Pharmacodynamic Eosinophils (PDe) Population which included all participants receiving at least one dose of mepolizumab beginning at Visit 2 (Week 0) and having at least one Part A blood sample evaluable for blood eosinophil count.
Number of Participants With on Treatment Serious Adverse Events (SAEs) and Non-SAEs for Part B	From Week 20 and up to Week 72	An AE is any untoward medical occurrence in a participant or clinical investigation participant, temporally associated with the use of a medicinal product, whether or not considered related to the medicinal product. Any untoward event resulting in death, life threatening, requires hospitalization or prolongation of existing hospitalization, results in disability/incapacity, congenital anomaly/birth defect, any other situation according to medical or scientific judgment or all events of possible drug-induced liver injury with hyperbilirubinemia are to be categorized as SAE. On-treatment SAEs and non-SAEs are defined as events occurring from the first Part B dose until 28 days following the last Part B dose. Safety Population includes all participants who received at least one dose of mepolizumab beginning at Visit 9.
Number of Participants With Positive Anti-mepolizumab Binding Antibodies and Neutralizing Antibodies Response for Part B	From Week 20 and up to Week 80	Blood sample were collected for the determination of anti-mepolizumab binding antibodies and neutralizing antibodies response in Part B at Weeks 44, 68 and 80 prior to study treatment administration. Participant was considered 'Positive' if they had at least one positive post-Baseline anti-drug antibody assay result. All Part B visits (including scheduled and unscheduled) post-Baseline were considered for Any-time Post-Baseline visit derivation. The number of participants with positive anti-mepolizumab binding antibodies and neutralizing antibodies response at Any Time Post Baseline has been presented. The neutralizing antibodies response results only presented for participants with positive anti-drug antibody assay.
Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Baseline and Weeks 24, 28, 32, 36, 40, 44, 48, 52, 56, 60, 64, 68, 72, 80	Sitting blood pressure measurements included SBP and DBP. Measurements were done pre-infusion/injection with the participant sitting, having rested in this position for at least 5 minutes before each reading. The Baseline was defined as the latest value recorded prior to the first dose of mepolizumab. Change from Baseline was defined as value at indicated time point minus Baseline value. Only those participants with data available at the specified time points were analyzed (represented by n=X in the category titles).
Change From Baseline in Sitting Pulse Rate for Part B	Baseline and Weeks 24, 28, 32, 36, 40, 44, 48, 52, 56, 60, 64, 68, 72, 80	Sitting pulse rate measurements were performed pre-infusion/injection with the participant sitting, having rested in this position for at least 5 minutes before each reading. The Baseline was defined as the latest value recorded prior to the first dose of mepolizumab in Part A. Change from Baseline was defined as value at indicated time point minus Baseline value. Only those participants with data available at the specified time points were analyzed (represented by n=X in the category titles).
Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Baseline, from Week 20 and up to Week 72	Blood samples were collected for analysis of alanine aminotransferase (ALT), alkaline phosphatase (ALP), aspartate aminotransferase (AST), gamma glutamyl transferase (GGT), albumin, protein, bilirubin, creatinine, urate, direct bilirubin, calcium, carbon dioxide (CO2), chloride, glucose, potassium, sodium and urea. Baseline was defined as the latest value recorded prior to the first dose of mepolizumab in Part A. Change from Baseline was defined as value at indicated time point minus Baseline value. All Part B visits (scheduled and unscheduled) post-Baseline were considered for Any-time Post-Baseline visit derivation. If participant had at least one value for categories To Low and/or To High along with To Normal or No Change then participant was counted under To Low and/or To High. If participant had values which belong only to To Normal or No Change then participant was counted under To Normal or No Change only. Any Time Post-Baseline values have been presented.
Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Baseline, from Week 20 and up to Week 80	Blood samples were collected for analysis of basophils, eosinophils, leukocyte, monocyte, neutrophils, lymphocyte, platelets, mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), hemoglobin (Hgb), mean corpuscular volume (MCV), erythrocytes, hematocrit, and reticulocytes/erythrocytes (Ret/Ery). Baseline was defined as the latest value recorded prior to first dose of mepolizumab in Part A. Change from Baseline was defined as value at indicated time point minus Baseline value. All Part B visits (scheduled and unscheduled) post-Baseline were considered for Any-time Post-Baseline visit derivation. If participant had at least one value for categories To Low and/or To High along with To Normal or No Change then participant was counted under To Low and/or To High. If participant had values which belong only to To Normal or No Change then participant was counted under To Normal or No Change only. Any Time Post-Baseline values have been presented.
Number of Participants With Abnormal Findings for Urinalysis Parameters in Part B	From Week 20 and up to Week 72	Urine samples were collected from participants at indicated time points for analysis of urinalysis parameters including Specific gravity and potential of hydrogen (pH) of urine, presence of glucose, protein, blood and ketones in urine by dipstick test. Microscopic examination was performed if blood or protein was abnormal. Only those participants with data available at the specified time points were analyzed.

Secondary

Measure	Time frame	Description
Body Weight-adjusted Apparent Clearance of Mepolizumab for Part A	Pre-dose on Weeks 4 and 8; Weeks 9, 12, 16 and 20 post-dose	PK samples were collected at pre-dose on Weeks 4 and 8; and at Weeks 9, 12, 16 and 20 post-dose. The body weight-adjusted apparent clearance was compared between adults and participants aged 6 to 11 years old with severe eosinophilic asthma when mepolizumab was administered subcutaneously. Point estimate and 90% confidence interval (CI) for participants aged 6 to 11 years (centered to a mean bodyweight of 70 kg) was compared with the historic adult estimated body-weight adjusted clearance of 0.22 L/day, around which a proposed 80-125% interval was applied i.e. 0.18-0.28 L/day. Assuming an absolute bioavailability of 75% this corresponds to an apparent clearance of 0.29 L/day with the proposed 80% to 125% interval of 0.23 to 0.36 L/day. Note the average bodyweight of 70kg (mean body weight observed in adults) was not observed in the study.
Ratio to Baseline in Absolute Blood Eosinophil Count at Weeks 32, 44, 56, 68, 72 and 80 for Part B	Baseline and Weeks 32, 44, 56, 68, 72 and 80	Blood samples were collected at the indicated time points for the analysis of eosinophil count. Baseline was defined as the latest value recorded prior to the first dose of mepolizumab in Part A. Ratio to Baseline was calculated as post-dose visit value/Baseline value. The analysis was based on Pharmacodynamic (Blood Eosinophils) (PDe) Population comprised of all participants receiving at least one dose of mepolizumab beginning at Visit 9 and having at least one Part B blood sample taken for blood eosinophil count. Only those participants with data available at the specified time points were analyzed (represented by n=X in the category titles).
Change From Baseline in Asthma Control Questionnaire-7 (ACQ-7) at Week 12 in Part A	Baseline and Week 12	ACQ-7 is a simple questionnaire to measure the adequacy of asthma control and change in asthma control which occurs either spontaneously or a result of treatment. The ACQ-7 uses a 7-point scale (0=no impairment, 6= maximum impairment for symptoms and rescue use; and 7 = category for forced expiratory volume in 1 second \[FEV1\]%). The instrument has a reported high test-retest reproducibility with an intraclass correlation coefficient =0.90. The minimally important change in score is 0.5. Baseline was defined as the latest value recorded prior to the first dose of mepolizumab. Change from Baseline was calculated as score obtained at Week 12 minus Baseline Score. Pharmacodynamic Outcome (PDo) Population included all participants who received at least one dose of mepolizumab beginning at Visit 2 and having at least one Part A assessment of pharmacodynamic outcomes.
Change From Baseline in Asthma Control Questionnaire-7 (ACQ-7) at Weeks 4,8,16 and 20 in Part A	Baseline and Weeks 4,8,16 and 20	ACQ-7 is a simple questionnaire to measure the adequacy of asthma control and change in asthma control which occurs either spontaneously or a result of treatment. The ACQ-7 uses a 7-point scale (0=no impairment, 6= maximum impairment for symptoms and rescue use; and 7=category for FEV1%). The instrument has a reported high test-retest reproducibility with an intraclass correlation coefficient =0.90. The minimally important change in score is 0.5. Baseline was defined as the latest value recorded prior to the first dose of mepolizumab. Change from Baseline was calculated as score obtained at the indicated time point minus Baseline Score. Only those participants with data available at the specified time points were analyzed (represented by n=X in the category titles).
Change From Baseline in Childhood Asthma Control Test (C-ACT) at Week 12 for Part A	Baseline and Week 12	The C-ACT assesses asthma control in children 4-11 years of age. The C-ACT is a 7-question, 2-part questionnaire, with items 1 to 4 were completed by the child (with assistance from a caregiver, as needed) and items 5 to 7 were completed by the caregiver. A total sum score based upon responses to all items was calculated to provide an overall measure of asthma control. The derived C-ACT score ranges from 0 (maximum impairment) to 27 (no impairment), where higher scores represent a better outcome. Baseline was defined as the latest value recorded prior to the first dose of mepolizumab. Change from Baseline was calculated as score obtained at Week 12 minus Baseline Score.
Change From Baseline in C-ACT at Weeks 4,8,16 and 20 in Part A	Baseline and Weeks 4,8,16 and 20	The C-ACT assesses asthma control in children 4-11 years of age. The C-ACT is a 7-question, 2-part questionnaire, with items 1 to 4 were completed by the child (with assistance from a caregiver, as needed) and items 5 to 7 were completed by the caregiver. A total sum score based upon responses to all items was calculated to provide an overall measure of asthma control. The derived C-ACT score ranges from 0 (maximum impairment) to 27 (no impairment), where higher scores represent a better outcome. Baseline was defined as the latest value recorded prior to the first dose of mepolizumab. Change from Baseline was calculated as score obtained at the indicated time point minus Baseline Score. Only those participants with data available at the specified time points were analyzed (represented by n=X in the category titles).
Number of Participants With on Treatment SAEs and Non-SAEs in Part A	Up to Week 20	An AE is any untoward medical occurrence in a participant or clinical investigation participant, temporally associated with the use of a medicinal product, whether or not considered related to the medicinal product. Any untoward event resulting in death, life threatening, requires hospitalization or prolongation of existing hospitalization, results in disability/incapacity, congenital anomaly/birth defect, any other situation according to medical or scientific judgment or all events of possible drug-induced liver injury with hyperbilirubinemia were categorized as SAE. Participants who received any of the study treatment and had any on-treatment non-SAE or SAE (defined as events occurring from the first dose until 28 days after the last dose of mepolizumab) were considered for analysis.
Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Baseline and up to Week 20	Blood samples were collected for analysis of basophils, eosinophils, leukocyte, monocyte, neutrophils, lymphocyte, platelet count, MCH, MCHC, Hgb, MCV, erythrocytes, hematocrit, and Ret/Ery. The Baseline was the latest value recorded prior to the first dose of mepolizumab. Change from Baseline was defined as value at indicated time point minus Baseline value. Any time post Baseline = all visits (scheduled and unscheduled) post Baseline was considered for this visit derivation. If participant had at least one value for categories To Low and/or To High along with To Normal or No Change then participant was counted under To Low and/or To High. If participant had values which belong only to To Normal or No Change then participant was counted under To Normal or No Change only. Only those participants with data available at the specified time points were analyzed (represented by n=X in the category titles). Any Time Post-Baseline values have been presented.
Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Baseline and up to Week 20	Blood samples were collected for analysis of ALT, ALP, AST, GGT, albumin, protein, total billirubin, creatinine, direct billirubin, urate, calcium, CO2, chloride, glucose, potassium, sodium and urea. Baseline was defined as the latest value recorded prior to the first dose of mepolizumab. Change from Baseline was defined as value at indicated time point minus Baseline value. Any time post Baseline = all visits (including scheduled and unscheduled) post Baseline was considered for this visit derivation. If participant had at least one value for categories To Low and/or To High along with To Normal or No Change then participant was counted under To Low and/or To High. If participant had values which belong only to To Normal or No Change then participant was counted under To Normal or No Change only. Any Time Post-Baseline values have been presented.
Number of Participants With Abnormal Findings for Urinalysis in Part A	Up to Week 20	Urine samples were collected from participants at indicated time points for analysis of urinalysis parameters including specific gravity and pH of urine, presence of glucose, protein, blood and ketones in urine by dipstick test. Microscopic examination was performed if blood or protein was abnormal. Only those participants with data available at the specified time points were analyzed.
Number of Participants With Positive Anti-mepolizumab Binding Antibodies and Neutralizing Antibodies Response in Part A	Baseline and Weeks 16 and 20	Blood sample for immunogenicity was collected for anti-mepolizumab binding antibodies and neutralizing antibodies response in Part A at indicated time points prior to study treatment administration. Number of participants with positive anti-mepolizumab binding antibodies and neutralizing antibodies response was summarized. Participant was considered 'Positive' if they had at least one positive post-baseline assay result. Any Time Post Baseline has been presented, which included all visits (including scheduled and unscheduled) post-baseline was considered for this visit derivation. Only those participants with data available at the specified time points were analyzed (represented by n=X in the category titles).
Change From Baseline in Sitting SBP and DBP in Part A	Baseline and Weeks 4, 8, 9, 12, 16 and 20	Sitting blood pressure measurements were performed in Part A at indicated time points. Measurements were done pre-infusion/injection with the participant sitting, having rested in this position for at least 5 minutes before each reading. The Baseline was defined as the latest value recorded prior to the first dose of mepolizumab. Change from Baseline was defined as value at indicated time point minus Baseline value. Only those participants with data available at the specified time points were analyzed (represented by n=X in the category titles).
Change From Baseline in Sitting Pulse Rate in Part A	Baseline and Weeks 4, 8, 9, 12, 16 and 20	Sitting pulse rate measurements was performed in Part A at indicated time points. Measurements were done pre-infusion/injection with the participant sitting, having rested in this position for at least 5 minutes before each reading. The Baseline was defined as the latest value recorded prior to the first dose of mepolizumab. Change from Baseline was defined as value at indicated time point minus Baseline value. Only those participants with data available at the specified time points were analyzed (represented by n=X in the category titles).

Countries

Japan, Poland, United Kingdom, United States

Participant flow

Recruitment details

This was a multi-center, open-label study to assess the pharmacokinetics (PK) and pharmacodynamics (PD) of mepolizumab 40 or 100 milligrams (mg) subcutaneously administered to participants with severe eosinophilic asthma aged 6-11 years. This study consisted of two parts: Part A and Part B.

Pre-assignment details

Part A consisted of pre-screening/ screening/ run-in, treatment, and Follow-up. Part B was long-term treatment and Follow-up phase. A total of 44 participants were screened and 36 were enrolled in Part A. Of which, 30 participants continued on treatment in Part B. Study was conducted in 4 countries (Japan, Poland, United Kingdom and United States).

Participants by arm

Arm	Count
Part A: Mepolizumab 40 mg SC Participants with bodyweight \< 40 kilogram (kg) received 0.4 milliliter (mL) of reconstituted mepolizumab subcutaneously every four weeks, in upper arm or thigh directly from the investigator or designee, under medical supervision. Participant's weight at Week 0 (Visit 2) was considered to select dosage in Part A. Prior to administration, each vial of mepolizumab were reconstituted and swirled gently to enable complete dissolution of the product.	26
Part A: Mepolizumab 100 mg SC Participants with bodyweight \>= 40 kg received 1.0 mL of reconstituted mepolizumab subcutaneously every four weeks, in upper arm or thigh directly from the investigator or designee, under medical supervision. Prior to administration, each vial of mepolizumab were reconstituted and swirled gently to enable complete dissolution of the product. On investigator discretion, injected volume was split between two injection sites and was given as 2 injections of 0.5 mL each if required.	10
Total	36

Withdrawals & dropouts

Period	Reason	FG000	FG002
Part A (Up to Week 20)	Other: AE of Asthma Exacerbation	1	0
Part A (Up to Week 20)	Physician Decision	1	0
Part A (Up to Week 20)	Withdrawal by Subject	2	0
Part B (From Week 20 and up to Week 80)	Protocol Violation	0	1

Baseline characteristics

Characteristic	Part A: Mepolizumab 100 mg SC	Total	Part A: Mepolizumab 40 mg SC
Age, Continuous	10.0 Years STANDARD_DEVIATION 1.33	8.6 Years STANDARD_DEVIATION 1.89	8.0 Years STANDARD_DEVIATION 1.79
Race/Ethnicity, Customized Black or African American (B or Af Am)	3 Participants	7 Participants	4 Participants
Race/Ethnicity, Customized B or Af Am and White-White/Caucasian/European Her.	0 Participants	1 Participants	1 Participants
Race/Ethnicity, Customized Central/South Asian Heritage (Her.)	0 Participants	1 Participants	1 Participants
Race/Ethnicity, Customized Japanese Her.	1 Participants	7 Participants	6 Participants
Race/Ethnicity, Customized White/Caucasian/European Her.	6 Participants	20 Participants	14 Participants
Sex: Female, Male Female	5 Participants	11 Participants	6 Participants
Sex: Female, Male Male	5 Participants	25 Participants	20 Participants

Adverse events

Event type	EG000 affected / at risk	EG001 affected / at risk	EG002 affected / at risk	EG003 affected / at risk	EG004 affected / at risk
deaths Total, all-cause mortality	0 / 26	0 / 10	0 / 16	0 / 10	0 / 4
other Total, other adverse events	18 / 26	6 / 10	15 / 16	8 / 10	4 / 4
serious Total, serious adverse events	5 / 26	1 / 10	4 / 16	2 / 10	1 / 4

Outcome results

Primary

Area Under Concentration Time Curve to Infinity (AUC [0-inf]) of Mepolizumab for Part A

PK of mepolizumab was evaluated in participants using AUC (0-inf). PK samples were collected at pre-dose on Weeks 4 and 8; and at Weeks 9, 12, 16 and 20 post-dose. AUC (0-inf) was evaluated by population PK methods and mean and standard error from the final model has been tabulated. Estimates have been presented from the final model centered to mean bodyweights of 27 kg, 50 kg and 70 kg. Note the average bodyweight of 70kg (mean body weight observed in adults) was not investigated in the study.

Time frame: Pre-dose on Weeks 4 and 8; Weeks 9, 12, 16 and 20 post-dose

Population: PK Population

Arm	Measure	Group	Value (MEAN)	Dispersion
Part A: Mepolizumab SC	Area Under Concentration Time Curve to Infinity (AUC [0-inf]) of Mepolizumab for Part A	70 kg	508.23 Day*ug per mL	Standard Error 41.8036
Part A: Mepolizumab SC	Area Under Concentration Time Curve to Infinity (AUC [0-inf]) of Mepolizumab for Part A	50 kg	675.20 Day*ug per mL	Standard Error 35.898
Part A: Mepolizumab SC	Area Under Concentration Time Curve to Infinity (AUC [0-inf]) of Mepolizumab for Part A	27 kg	454.39 Day*ug per mL	Standard Error 15.8876

Primary

Change From Baseline in Sitting Pulse Rate for Part B

Sitting pulse rate measurements were performed pre-infusion/injection with the participant sitting, having rested in this position for at least 5 minutes before each reading. The Baseline was defined as the latest value recorded prior to the first dose of mepolizumab in Part A. Change from Baseline was defined as value at indicated time point minus Baseline value. Only those participants with data available at the specified time points were analyzed (represented by n=X in the category titles).

Time frame: Baseline and Weeks 24, 28, 32, 36, 40, 44, 48, 52, 56, 60, 64, 68, 72, 80

Population: Safety Population

Arm	Measure	Group	Value (MEAN)	Dispersion
Part A: Mepolizumab SC	Change From Baseline in Sitting Pulse Rate for Part B	Sitting pulse rate, Week 64, n= 15, 9, 3	-2.0 Beats per minute	Standard Deviation 11.16
Part A: Mepolizumab SC	Change From Baseline in Sitting Pulse Rate for Part B	Sitting pulse rate, Week 44, n= 15, 9, 3	-0.7 Beats per minute	Standard Deviation 13.56
Part A: Mepolizumab SC	Change From Baseline in Sitting Pulse Rate for Part B	Sitting pulse rate, Week 24, n= 16, 9, 4	-3.8 Beats per minute	Standard Deviation 5.8
Part A: Mepolizumab SC	Change From Baseline in Sitting Pulse Rate for Part B	Sitting pulse rate, Week 60, n= 15, 9, 3	-3.4 Beats per minute	Standard Deviation 11.18
Part A: Mepolizumab SC	Change From Baseline in Sitting Pulse Rate for Part B	Sitting pulse rate, Week 48, n= 15, 9, 3	-2.3 Beats per minute	Standard Deviation 11.29
Part A: Mepolizumab SC	Change From Baseline in Sitting Pulse Rate for Part B	Sitting pulse rate, Week 72, n= 15, 10, 4	-5.3 Beats per minute	Standard Deviation 8.66
Part A: Mepolizumab SC	Change From Baseline in Sitting Pulse Rate for Part B	Sitting pulse rate, Week 56, n= 15, 9, 3	-3.8 Beats per minute	Standard Deviation 8.9
Part A: Mepolizumab SC	Change From Baseline in Sitting Pulse Rate for Part B	Sitting pulse rate, Week 52, n= 15, 9, 3	-1.3 Beats per minute	Standard Deviation 8.41
Part A: Mepolizumab SC	Change From Baseline in Sitting Pulse Rate for Part B	Sitting pulse rate, Week 32, n= 15, 9, 3	-4.8 Beats per minute	Standard Deviation 9.75
Part A: Mepolizumab SC	Change From Baseline in Sitting Pulse Rate for Part B	Sitting pulse rate, Week 36, n= 15, 8, 3	-0.5 Beats per minute	Standard Deviation 11.3
Part A: Mepolizumab SC	Change From Baseline in Sitting Pulse Rate for Part B	Sitting pulse rate, Week 80, n= 11, 9, 2	-2.5 Beats per minute	Standard Deviation 3.33
Part A: Mepolizumab SC	Change From Baseline in Sitting Pulse Rate for Part B	Sitting pulse rate, Week 68, n= 15, 9, 3	-0.9 Beats per minute	Standard Deviation 8.03
Part A: Mepolizumab SC	Change From Baseline in Sitting Pulse Rate for Part B	Sitting pulse rate, Week 40, n= 15, 9, 3	-4.5 Beats per minute	Standard Deviation 10.84
Part A: Mepolizumab SC	Change From Baseline in Sitting Pulse Rate for Part B	Sitting pulse rate, Week 28, n= 15, 9, 3	-7.0 Beats per minute	Standard Deviation 9.02
Part A: Mepolizumab 100 mg SC	Change From Baseline in Sitting Pulse Rate for Part B	Sitting pulse rate, Week 64, n= 15, 9, 3	5.0 Beats per minute	Standard Deviation 11.26
Part A: Mepolizumab 100 mg SC	Change From Baseline in Sitting Pulse Rate for Part B	Sitting pulse rate, Week 24, n= 16, 9, 4	4.3 Beats per minute	Standard Deviation 7.5
Part A: Mepolizumab 100 mg SC	Change From Baseline in Sitting Pulse Rate for Part B	Sitting pulse rate, Week 28, n= 15, 9, 3	2.7 Beats per minute	Standard Deviation 4.92
Part A: Mepolizumab 100 mg SC	Change From Baseline in Sitting Pulse Rate for Part B	Sitting pulse rate, Week 32, n= 15, 9, 3	4.7 Beats per minute	Standard Deviation 10.3
Part A: Mepolizumab 100 mg SC	Change From Baseline in Sitting Pulse Rate for Part B	Sitting pulse rate, Week 36, n= 15, 8, 3	7.3 Beats per minute	Standard Deviation 12.28
Part A: Mepolizumab 100 mg SC	Change From Baseline in Sitting Pulse Rate for Part B	Sitting pulse rate, Week 40, n= 15, 9, 3	1.7 Beats per minute	Standard Deviation 14.04
Part A: Mepolizumab 100 mg SC	Change From Baseline in Sitting Pulse Rate for Part B	Sitting pulse rate, Week 44, n= 15, 9, 3	3.4 Beats per minute	Standard Deviation 12.3
Part A: Mepolizumab 100 mg SC	Change From Baseline in Sitting Pulse Rate for Part B	Sitting pulse rate, Week 48, n= 15, 9, 3	-0.6 Beats per minute	Standard Deviation 5.64
Part A: Mepolizumab 100 mg SC	Change From Baseline in Sitting Pulse Rate for Part B	Sitting pulse rate, Week 52, n= 15, 9, 3	-2.1 Beats per minute	Standard Deviation 9.03
Part A: Mepolizumab 100 mg SC	Change From Baseline in Sitting Pulse Rate for Part B	Sitting pulse rate, Week 56, n= 15, 9, 3	-1.9 Beats per minute	Standard Deviation 10.99
Part A: Mepolizumab 100 mg SC	Change From Baseline in Sitting Pulse Rate for Part B	Sitting pulse rate, Week 60, n= 15, 9, 3	-1.0 Beats per minute	Standard Deviation 13.86
Part A: Mepolizumab 100 mg SC	Change From Baseline in Sitting Pulse Rate for Part B	Sitting pulse rate, Week 68, n= 15, 9, 3	-2.4 Beats per minute	Standard Deviation 9.18
Part A: Mepolizumab 100 mg SC	Change From Baseline in Sitting Pulse Rate for Part B	Sitting pulse rate, Week 72, n= 15, 10, 4	-0.3 Beats per minute	Standard Deviation 14.21
Part A: Mepolizumab 100 mg SC	Change From Baseline in Sitting Pulse Rate for Part B	Sitting pulse rate, Week 80, n= 11, 9, 2	2.1 Beats per minute	Standard Deviation 7.24
Part B: Mepolizumab 40/100 mg SC	Change From Baseline in Sitting Pulse Rate for Part B	Sitting pulse rate, Week 72, n= 15, 10, 4	-6.0 Beats per minute	Standard Deviation 6.83
Part B: Mepolizumab 40/100 mg SC	Change From Baseline in Sitting Pulse Rate for Part B	Sitting pulse rate, Week 60, n= 15, 9, 3	6.3 Beats per minute	Standard Deviation 14.43
Part B: Mepolizumab 40/100 mg SC	Change From Baseline in Sitting Pulse Rate for Part B	Sitting pulse rate, Week 40, n= 15, 9, 3	-4.0 Beats per minute	Standard Deviation 4
Part B: Mepolizumab 40/100 mg SC	Change From Baseline in Sitting Pulse Rate for Part B	Sitting pulse rate, Week 32, n= 15, 9, 3	-7.7 Beats per minute	Standard Deviation 12.01
Part B: Mepolizumab 40/100 mg SC	Change From Baseline in Sitting Pulse Rate for Part B	Sitting pulse rate, Week 64, n= 15, 9, 3	8.3 Beats per minute	Standard Deviation 16.86
Part B: Mepolizumab 40/100 mg SC	Change From Baseline in Sitting Pulse Rate for Part B	Sitting pulse rate, Week 36, n= 15, 8, 3	8.0 Beats per minute	Standard Deviation 7
Part B: Mepolizumab 40/100 mg SC	Change From Baseline in Sitting Pulse Rate for Part B	Sitting pulse rate, Week 24, n= 16, 9, 4	7.0 Beats per minute	Standard Deviation 16.51
Part B: Mepolizumab 40/100 mg SC	Change From Baseline in Sitting Pulse Rate for Part B	Sitting pulse rate, Week 68, n= 15, 9, 3	-4.3 Beats per minute	Standard Deviation 10.97
Part B: Mepolizumab 40/100 mg SC	Change From Baseline in Sitting Pulse Rate for Part B	Sitting pulse rate, Week 28, n= 15, 9, 3	1.7 Beats per minute	Standard Deviation 9.61
Part B: Mepolizumab 40/100 mg SC	Change From Baseline in Sitting Pulse Rate for Part B	Sitting pulse rate, Week 52, n= 15, 9, 3	11.7 Beats per minute	Standard Deviation 4.16
Part B: Mepolizumab 40/100 mg SC	Change From Baseline in Sitting Pulse Rate for Part B	Sitting pulse rate, Week 48, n= 15, 9, 3	-3.0 Beats per minute	Standard Deviation 8.19
Part B: Mepolizumab 40/100 mg SC	Change From Baseline in Sitting Pulse Rate for Part B	Sitting pulse rate, Week 80, n= 11, 9, 2	13.0 Beats per minute	Standard Deviation 9.9
Part B: Mepolizumab 40/100 mg SC	Change From Baseline in Sitting Pulse Rate for Part B	Sitting pulse rate, Week 56, n= 15, 9, 3	-0.3 Beats per minute	Standard Deviation 6.66
Part B: Mepolizumab 40/100 mg SC	Change From Baseline in Sitting Pulse Rate for Part B	Sitting pulse rate, Week 44, n= 15, 9, 3	4.0 Beats per minute	Standard Deviation 19.31

Primary

Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B

Sitting blood pressure measurements included SBP and DBP. Measurements were done pre-infusion/injection with the participant sitting, having rested in this position for at least 5 minutes before each reading. The Baseline was defined as the latest value recorded prior to the first dose of mepolizumab. Change from Baseline was defined as value at indicated time point minus Baseline value. Only those participants with data available at the specified time points were analyzed (represented by n=X in the category titles).

Time frame: Baseline and Weeks 24, 28, 32, 36, 40, 44, 48, 52, 56, 60, 64, 68, 72, 80

Population: Safety Population

Arm	Measure	Group	Value (MEAN)	Dispersion
Part A: Mepolizumab SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting SBP, Week 44, n=15, 9, 3	4.3 Millimeter of mercury	Standard Deviation 8.5
Part A: Mepolizumab SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting DBP, Week 60, n=15,9,3	0.8 Millimeter of mercury	Standard Deviation 4.8
Part A: Mepolizumab SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting SBP, Week 80, n= 12, 9, 2	3.3 Millimeter of mercury	Standard Deviation 4.33
Part A: Mepolizumab SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting SBP, Week 40, n=15, 9, 3	5.5 Millimeter of mercury	Standard Deviation 7.85
Part A: Mepolizumab SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting DBP, Week 64, n=15,9,3	1.7 Millimeter of mercury	Standard Deviation 3.48
Part A: Mepolizumab SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting SBP, Week 64, n=15, 9, 3	5.5 Millimeter of mercury	Standard Deviation 7.98
Part A: Mepolizumab SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting SBP, Week 36, n=15, 8, 3	6.3 Millimeter of mercury	Standard Deviation 9.13
Part A: Mepolizumab SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting DBP, Week 68, n=15,9,3	3.3 Millimeter of mercury	Standard Deviation 7.08
Part A: Mepolizumab SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting DBP, Week 24, n=16,9, 4	1.4 Millimeter of mercury	Standard Deviation 4.22
Part A: Mepolizumab SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting SBP, Week 32, n=15, 9, 3	2.9 Millimeter of mercury	Standard Deviation 5.59
Part A: Mepolizumab SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting DBP, Week 72, n=15,10,4	2.5 Millimeter of mercury	Standard Deviation 6.15
Part A: Mepolizumab SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting SBP, Week 60, n=15, 9, 3	5.7 Millimeter of mercury	Standard Deviation 8.33
Part A: Mepolizumab SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting SBP, Week 28, n=15, 9, 3	9.3 Millimeter of mercury	Standard Deviation 6.11
Part A: Mepolizumab SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting DBP, Week 80, n=12 ,9,2	1.3 Millimeter of mercury	Standard Deviation 4.6
Part A: Mepolizumab SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting DBP, Week 40, n=15,9,3	2.3 Millimeter of mercury	Standard Deviation 8.4
Part A: Mepolizumab SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting SBP, Week 24, n=16, 9, 4	3.3 Millimeter of mercury	Standard Deviation 7.44
Part A: Mepolizumab SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting DBP, Week 36, n=15,8,3	3.6 Millimeter of mercury	Standard Deviation 4.73
Part A: Mepolizumab SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting SBP, Week 56, n=15, 9, 3	4.9 Millimeter of mercury	Standard Deviation 7.81
Part A: Mepolizumab SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting DBP, Week 44, n=15,9 ,3	1.4 Millimeter of mercury	Standard Deviation 5.62
Part A: Mepolizumab SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting SBP, Week 72, n=15, 10, 4	6.4 Millimeter of mercury	Standard Deviation 5.79
Part A: Mepolizumab SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting SBP, Week 52, n=15, 9, 3	7.8 Millimeter of mercury	Standard Deviation 7.19
Part A: Mepolizumab SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting DBP, Week 48, n=15,9,3	3.5 Millimeter of mercury	Standard Deviation 7.5
Part A: Mepolizumab SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting DBP, Week 28, n=15,9, 3	5.7 Millimeter of mercury	Standard Deviation 7.13
Part A: Mepolizumab SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting SBP, Week 48, n=15, 9, 3	5.5 Millimeter of mercury	Standard Deviation 8.25
Part A: Mepolizumab SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting DBP, Week 52, n=15,9,3	3.5 Millimeter of mercury	Standard Deviation 7.55
Part A: Mepolizumab SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting SBP, Week 68, n=15, 9, 3	8.6 Millimeter of mercury	Standard Deviation 8.58
Part A: Mepolizumab SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting DBP, Week 56, n=15,9,3	2.2 Millimeter of mercury	Standard Deviation 8.47
Part A: Mepolizumab SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting DBP, Week 32, n=15 ,9,3	2.3 Millimeter of mercury	Standard Deviation 5.65
Part A: Mepolizumab 100 mg SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting DBP, Week 28, n=15,9, 3	1.6 Millimeter of mercury	Standard Deviation 5.53
Part A: Mepolizumab 100 mg SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting SBP, Week 44, n=15, 9, 3	3.8 Millimeter of mercury	Standard Deviation 8.32
Part A: Mepolizumab 100 mg SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting SBP, Week 72, n=15, 10, 4	2.7 Millimeter of mercury	Standard Deviation 10.93
Part A: Mepolizumab 100 mg SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting DBP, Week 24, n=16,9, 4	-0.9 Millimeter of mercury	Standard Deviation 6.68
Part A: Mepolizumab 100 mg SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting DBP, Week 32, n=15 ,9,3	3.0 Millimeter of mercury	Standard Deviation 7.37
Part A: Mepolizumab 100 mg SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting DBP, Week 36, n=15,8,3	4.9 Millimeter of mercury	Standard Deviation 11.14
Part A: Mepolizumab 100 mg SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting DBP, Week 40, n=15,9,3	4.2 Millimeter of mercury	Standard Deviation 6.82
Part A: Mepolizumab 100 mg SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting DBP, Week 44, n=15,9 ,3	6.2 Millimeter of mercury	Standard Deviation 7.61
Part A: Mepolizumab 100 mg SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting DBP, Week 48, n=15,9,3	4.1 Millimeter of mercury	Standard Deviation 6.15
Part A: Mepolizumab 100 mg SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting DBP, Week 52, n=15,9,3	1.4 Millimeter of mercury	Standard Deviation 5.05
Part A: Mepolizumab 100 mg SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting DBP, Week 56, n=15,9,3	3.6 Millimeter of mercury	Standard Deviation 7.14
Part A: Mepolizumab 100 mg SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting DBP, Week 60, n=15,9,3	6.3 Millimeter of mercury	Standard Deviation 10.77
Part A: Mepolizumab 100 mg SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting DBP, Week 64, n=15,9,3	3.9 Millimeter of mercury	Standard Deviation 8.12
Part A: Mepolizumab 100 mg SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting DBP, Week 68, n=15,9,3	5.3 Millimeter of mercury	Standard Deviation 7.6
Part A: Mepolizumab 100 mg SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting DBP, Week 72, n=15,10,4	5.4 Millimeter of mercury	Standard Deviation 10.42
Part A: Mepolizumab 100 mg SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting DBP, Week 80, n=12 ,9,2	7.4 Millimeter of mercury	Standard Deviation 7.6
Part A: Mepolizumab 100 mg SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting SBP, Week 24, n=16, 9, 4	-2.4 Millimeter of mercury	Standard Deviation 13.87
Part A: Mepolizumab 100 mg SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting SBP, Week 28, n=15, 9, 3	-0.6 Millimeter of mercury	Standard Deviation 13.47
Part A: Mepolizumab 100 mg SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting SBP, Week 32, n=15, 9, 3	5.6 Millimeter of mercury	Standard Deviation 12.04
Part A: Mepolizumab 100 mg SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting SBP, Week 36, n=15, 8, 3	9.4 Millimeter of mercury	Standard Deviation 11.84
Part A: Mepolizumab 100 mg SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting SBP, Week 40, n=15, 9, 3	4.6 Millimeter of mercury	Standard Deviation 9.74
Part A: Mepolizumab 100 mg SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting SBP, Week 48, n=15, 9, 3	4.2 Millimeter of mercury	Standard Deviation 11.09
Part A: Mepolizumab 100 mg SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting SBP, Week 52, n=15, 9, 3	-1.2 Millimeter of mercury	Standard Deviation 12.04
Part A: Mepolizumab 100 mg SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting SBP, Week 56, n=15, 9, 3	2.1 Millimeter of mercury	Standard Deviation 10.33
Part A: Mepolizumab 100 mg SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting SBP, Week 60, n=15, 9, 3	2.3 Millimeter of mercury	Standard Deviation 16.5
Part A: Mepolizumab 100 mg SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting SBP, Week 64, n=15, 9, 3	5.2 Millimeter of mercury	Standard Deviation 12.09
Part A: Mepolizumab 100 mg SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting SBP, Week 68, n=15, 9, 3	5.6 Millimeter of mercury	Standard Deviation 8.75
Part A: Mepolizumab 100 mg SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting SBP, Week 80, n= 12, 9, 2	3.6 Millimeter of mercury	Standard Deviation 11.82
Part B: Mepolizumab 40/100 mg SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting DBP, Week 60, n=15,9,3	-2.3 Millimeter of mercury	Standard Deviation 8.08
Part B: Mepolizumab 40/100 mg SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting DBP, Week 28, n=15,9, 3	-4.0 Millimeter of mercury	Standard Deviation 7
Part B: Mepolizumab 40/100 mg SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting SBP, Week 40, n=15, 9, 3	-9.3 Millimeter of mercury	Standard Deviation 12.22
Part B: Mepolizumab 40/100 mg SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting DBP, Week 56, n=15,9,3	-0.3 Millimeter of mercury	Standard Deviation 8.02
Part B: Mepolizumab 40/100 mg SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting SBP, Week 44, n=15, 9, 3	3.0 Millimeter of mercury	Standard Deviation 9.54
Part B: Mepolizumab 40/100 mg SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting DBP, Week 48, n=15,9,3	8.7 Millimeter of mercury	Standard Deviation 3.21
Part B: Mepolizumab 40/100 mg SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting SBP, Week 80, n= 12, 9, 2	11.5 Millimeter of mercury	Standard Deviation 0.71
Part B: Mepolizumab 40/100 mg SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting SBP, Week 48, n=15, 9, 3	3.3 Millimeter of mercury	Standard Deviation 11.68
Part B: Mepolizumab 40/100 mg SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting DBP, Week 44, n=15,9 ,3	3.7 Millimeter of mercury	Standard Deviation 11.85
Part B: Mepolizumab 40/100 mg SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting SBP, Week 68, n=15, 9, 3	4.3 Millimeter of mercury	Standard Deviation 10.02
Part B: Mepolizumab 40/100 mg SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting SBP, Week 52, n=15, 9, 3	-5.0 Millimeter of mercury	Standard Deviation 17.32
Part B: Mepolizumab 40/100 mg SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting DBP, Week 40, n=15,9,3	-3.7 Millimeter of mercury	Standard Deviation 4.73
Part B: Mepolizumab 40/100 mg SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting DBP, Week 24, n=16,9, 4	-0.8 Millimeter of mercury	Standard Deviation 3.59
Part B: Mepolizumab 40/100 mg SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting SBP, Week 56, n=15, 9, 3	-9.7 Millimeter of mercury	Standard Deviation 15.04
Part B: Mepolizumab 40/100 mg SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting DBP, Week 36, n=15,8,3	1.7 Millimeter of mercury	Standard Deviation 8.62
Part B: Mepolizumab 40/100 mg SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting SBP, Week 72, n=15, 10, 4	-3.3 Millimeter of mercury	Standard Deviation 9.22
Part B: Mepolizumab 40/100 mg SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting DBP, Week 80, n=12 ,9,2	0.5 Millimeter of mercury	Standard Deviation 13.44
Part B: Mepolizumab 40/100 mg SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting SBP, Week 60, n=15, 9, 3	-3.3 Millimeter of mercury	Standard Deviation 17.62
Part B: Mepolizumab 40/100 mg SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting SBP, Week 24, n=16, 9, 4	-6.3 Millimeter of mercury	Standard Deviation 6.95
Part B: Mepolizumab 40/100 mg SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting DBP, Week 72, n=15,10,4	0.5 Millimeter of mercury	Standard Deviation 10.21
Part B: Mepolizumab 40/100 mg SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting DBP, Week 32, n=15 ,9,3	1.0 Millimeter of mercury	Standard Deviation 12.49
Part B: Mepolizumab 40/100 mg SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting SBP, Week 28, n=15, 9, 3	-1.0 Millimeter of mercury	Standard Deviation 5.57
Part B: Mepolizumab 40/100 mg SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting DBP, Week 68, n=15,9,3	-2.0 Millimeter of mercury	Standard Deviation 10.58
Part B: Mepolizumab 40/100 mg SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting DBP, Week 52, n=15,9,3	-3.3 Millimeter of mercury	Standard Deviation 9.61
Part B: Mepolizumab 40/100 mg SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting SBP, Week 32, n=15, 9, 3	-2.7 Millimeter of mercury	Standard Deviation 16.5
Part B: Mepolizumab 40/100 mg SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting DBP, Week 64, n=15,9,3	0.7 Millimeter of mercury	Standard Deviation 3.06
Part B: Mepolizumab 40/100 mg SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting SBP, Week 64, n=15, 9, 3	-1.3 Millimeter of mercury	Standard Deviation 15.89
Part B: Mepolizumab 40/100 mg SC	Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B	Sitting SBP, Week 36, n=15, 8, 3	-1.3 Millimeter of mercury	Standard Deviation 6.43

Primary

Maximum Plasma Concentration (Cmax) of Mepolizumab for Part A

PK of mepolizumab was evaluated in participants using Cmax. PK samples were collected at pre-dose on Weeks 4 and 8; and at Weeks 9, 12, 16 and 20 post-dose. Cmax was evaluated by population PK methods and mean and standard error from the final model has been tabulated. Estimates have been presented from the final model centered to mean bodyweights of 27 kg, 50 kg and 70 kg. Note the average bodyweight of 70 kg (mean body weight observed in adults) was not investigated in the study. PK Population included all participants receiving at least one dose of mepolizumab beginning at Visit 2 (Week 0) and having at least one blood sample taken at Visit 3 (Week 4) or thereafter with measurable mepolizumab plasma concentration.

Time frame: Pre-dose on Weeks 4 and 8; Weeks 9, 12, 16 and 20 post-dose

Population: PK Population

Arm	Measure	Group	Value (MEAN)	Dispersion
Part A: Mepolizumab SC	Maximum Plasma Concentration (Cmax) of Mepolizumab for Part A	70 kg	12.8188 Microgram (ug) per mL	Standard Error 0.7843
Part A: Mepolizumab SC	Maximum Plasma Concentration (Cmax) of Mepolizumab for Part A	50 kg	16.3412 Microgram (ug) per mL	Standard Error 0.6364
Part A: Mepolizumab SC	Maximum Plasma Concentration (Cmax) of Mepolizumab for Part A	27 kg	10.1960 Microgram (ug) per mL	Standard Error 0.3345

Primary

Number of Participants With Abnormal Findings for Urinalysis Parameters in Part B

Urine samples were collected from participants at indicated time points for analysis of urinalysis parameters including Specific gravity and potential of hydrogen (pH) of urine, presence of glucose, protein, blood and ketones in urine by dipstick test. Microscopic examination was performed if blood or protein was abnormal. Only those participants with data available at the specified time points were analyzed.

Time frame: From Week 20 and up to Week 72

Population: Safety Population

Arm	Measure	Value (NUMBER)
Part A: Mepolizumab SC	Number of Participants With Abnormal Findings for Urinalysis Parameters in Part B	7 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Abnormal Findings for Urinalysis Parameters in Part B	6 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Abnormal Findings for Urinalysis Parameters in Part B	0 Participants

Primary

Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B

Blood samples were collected for analysis of alanine aminotransferase (ALT), alkaline phosphatase (ALP), aspartate aminotransferase (AST), gamma glutamyl transferase (GGT), albumin, protein, bilirubin, creatinine, urate, direct bilirubin, calcium, carbon dioxide (CO2), chloride, glucose, potassium, sodium and urea. Baseline was defined as the latest value recorded prior to the first dose of mepolizumab in Part A. Change from Baseline was defined as value at indicated time point minus Baseline value. All Part B visits (scheduled and unscheduled) post-Baseline were considered for Any-time Post-Baseline visit derivation. If participant had at least one value for categories To Low and/or To High along with To Normal or No Change then participant was counted under To Low and/or To High. If participant had values which belong only to To Normal or No Change then participant was counted under To Normal or No Change only. Any Time Post-Baseline values have been presented.

Time frame: Baseline, from Week 20 and up to Week 72

Population: Safety Population

Arm	Measure	Group	Value (NUMBER)
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Direct Bilirubin; To Low	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	ALP; To Low	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Sodium; To Normal or No Change	16 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Albumin; To High	1 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Sodium; To High	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Albumin; To Normal or No Change	15 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Urate; To Low	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Bilirubin; To Low	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Albumin; To Low	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Urate; To Normal or No Change	16 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	CO2; To High	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	ALT; To High	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Urate; To High	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	ALT; To Normal or No Change	16 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Urea; To Low	2 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	ALT; To Low	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Urea; To Normal or No Change	14 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Direct Bilirubin; To Normal or No Change	16 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Urea; To High	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	CO2; To Normal or No Change	10 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Direct Bilirubin; To High	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Chloride; To High	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Potassium; To Normal or No Change	16 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	CO2; To Low	6 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	GGT; To Normal or No Change	16 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Creatinine; To Low	2 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Calcium; To High	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	GGT; To High	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	GGT; To Low	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Calcium; To Normal or No Change	16 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Glucose; To Low	1 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Glucose; To High	5 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Calcium; To Low	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Glucose; To Normal or No Change	10 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Creatinine; To Normal or No Change	13 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Bilirubin; To High	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Potassium; To Low	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	ALP;To High	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Bilirubin; To Normal or No Change	16 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Chloride; To Normal or No Change	16 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Potassium; To High	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	AST; To High	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Protein; To Low	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Creatinine; To High	1 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	AST; To Normal or No Change	16 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Protein; To Normal or No Change	15 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Chloride; To Low	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	AST; To Low	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Protein; To High	1 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	ALP; To Normal or No Change	16 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Sodium; To Low	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	ALT; To Normal or No Change	10 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Creatinine; To Low	2 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Creatinine; To Normal or No Change	7 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Direct Bilirubin; To Low	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Direct Bilirubin; To Normal or No Change	10 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Direct Bilirubin; To High	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	GGT; To Low	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	GGT; To Normal or No Change	10 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	GGT; To High	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Glucose; To Low	2 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Glucose; To Normal or No Change	4 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Potassium; To Low	1 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Potassium; To Normal or No Change	9 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Protein; To Low	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Protein; To Normal or No Change	10 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Sodium; To Low	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Urate; To Low	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Urate; To Normal or No Change	10 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Urea; To Normal or No Change	9 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Urea; To High	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	ALT; To Low	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	ALT; To High	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Albumin; To Low	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Albumin; To Normal or No Change	10 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Albumin; To High	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	ALP; To Low	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	ALP; To Normal or No Change	10 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	ALP;To High	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	AST; To Low	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	AST; To Normal or No Change	10 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	AST; To High	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Bilirubin; To Low	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Bilirubin; To Normal or No Change	9 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Bilirubin; To High	1 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Calcium; To Low	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Calcium; To Normal or No Change	7 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Calcium; To High	3 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	CO2; To Low	3 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	CO2; To Normal or No Change	7 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	CO2; To High	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Chloride; To Low	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Chloride; To Normal or No Change	9 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Chloride; To High	1 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Glucose; To High	4 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Potassium; To High	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Protein; To High	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Sodium; To Normal or No Change	10 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Sodium; To High	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Urate; To High	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Urea; To Low	1 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Creatinine; To High	1 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Potassium; To High	0 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Chloride; To Low	0 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	AST; To High	0 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Creatinine; To Normal or No Change	4 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Bilirubin; To Low	0 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Potassium; To Low	0 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Direct Bilirubin; To High	0 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Bilirubin; To Normal or No Change	4 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Glucose; To High	3 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Chloride; To Normal or No Change	4 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Glucose; To Low	0 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Urea; To High	0 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Calcium; To Low	0 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	GGT; To High	0 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Glucose; To Normal or No Change	1 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Calcium; To Normal or No Change	3 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	GGT; To Normal or No Change	4 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Creatinine; To Low	0 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Calcium; To High	1 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Urea; To Normal or No Change	3 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	GGT; To Low	0 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Urea; To Low	1 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	ALP; To Low	0 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	ALT; To Low	0 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Urate; To High	0 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	ALT; To Normal or No Change	4 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Urate; To Normal or No Change	4 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	CO2; To Low	3 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	ALT; To High	0 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Urate; To Low	0 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Direct Bilirubin; To Normal or No Change	4 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Albumin; To Low	0 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Sodium; To High	0 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Chloride; To High	0 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Albumin; To Normal or No Change	4 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Sodium; To Normal or No Change	4 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	CO2; To Normal or No Change	1 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Albumin; To High	0 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Sodium; To Low	0 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Direct Bilirubin; To Low	0 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Protein; To High	0 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Potassium; To Normal or No Change	4 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	ALP; To Normal or No Change	4 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	CO2; To High	0 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	ALP;To High	0 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Protein; To Normal or No Change	4 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Creatinine; To High	0 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	AST; To Low	0 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Protein; To Low	0 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	Bilirubin; To High	0 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B	AST; To Normal or No Change	4 Participants

Primary

Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B

Blood samples were collected for analysis of basophils, eosinophils, leukocyte, monocyte, neutrophils, lymphocyte, platelets, mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), hemoglobin (Hgb), mean corpuscular volume (MCV), erythrocytes, hematocrit, and reticulocytes/erythrocytes (Ret/Ery). Baseline was defined as the latest value recorded prior to first dose of mepolizumab in Part A. Change from Baseline was defined as value at indicated time point minus Baseline value. All Part B visits (scheduled and unscheduled) post-Baseline were considered for Any-time Post-Baseline visit derivation. If participant had at least one value for categories To Low and/or To High along with To Normal or No Change then participant was counted under To Low and/or To High. If participant had values which belong only to To Normal or No Change then participant was counted under To Normal or No Change only. Any Time Post-Baseline values have been presented.

Time frame: Baseline, from Week 20 and up to Week 80

Population: Safety Population

Arm	Measure	Group	Value (NUMBER)
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Lymphocytes; To High	1 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Monocytes; To Normal or No Change	10 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	MCHC; To High	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Neutrophils; To High	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	MCH; To Normal or No Change	16 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Erythrocytes; To Low	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Lymphocytes; To Normal or No Change	15 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Erythrocytes; To Normal or No Change	15 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Eosinophils; To Normal or No Change	5 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Platelets; To Low	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Erythrocytes; To High	1 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Monocytes; To High	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	MCH; To High	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Hematocrit; To Low	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Platelets; To Normal or No Change	15 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	MCV; To Normal or No Change	16 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Hematocrit; To Normal or No Change	16 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Basophils; To High	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	MCHC;To Low	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Hematocrit; To High	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Platelets; To High	1 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	MCV; To High	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Hgb; To Low	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Neutrophils; To Low	3 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Ret/Ery; To Low	2 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Hgb; To Normal or No Change	16 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Monocytes; To Low	6 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	MCHC; To Normal or No Change	16 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Hgb; To High	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Eosinophils;To High	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Ret/Ery; To Normal or No Change	12 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Leukocytes; To Low	5 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Basophils; To Normal or No Change	16 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Eosinophils;To Low	11 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Leukocytes; To Normal or No Change	11 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	MCH; To Low	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Ret/Ery;To High	2 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Leukocytes; To High	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Neutrophils; To Normal or No Change	13 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	MCV; To Low	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Lymphocytes; To Low	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Basophils; To Low	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Lymphocytes; To Low	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Lymphocytes; To Normal or No Change	9 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Lymphocytes; To High	1 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Monocytes; To Low	2 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	MCV; To Normal or No Change	9 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Monocytes; To Normal or No Change	8 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Monocytes; To High	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Neutrophils; To Low	2 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	MCV; To High	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Neutrophils; To Normal or No Change	5 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Eosinophils; To Normal or No Change	4 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Neutrophils; To High	3 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Platelets; To Low	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Eosinophils;To High	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Platelets; To Normal or No Change	10 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Platelets; To High	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Basophils; To Normal or No Change	10 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Ret/Ery; To Low	3 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Ret/Ery; To Normal or No Change	7 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Ret/Ery;To High	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	MCH; To Low	1 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Basophils; To High	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	MCHC; To High	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Erythrocytes; To Low	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Erythrocytes; To Normal or No Change	8 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	MCH; To Normal or No Change	9 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Erythrocytes; To High	2 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Hematocrit; To Low	2 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	MCH; To High	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Hematocrit; To Normal or No Change	7 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Hematocrit; To High	1 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	MCHC;To Low	1 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Hgb; To Low	1 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Basophils; To Low	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Hgb; To Normal or No Change	8 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Hgb; To High	1 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	MCHC; To Normal or No Change	9 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Leukocytes; To Low	2 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Leukocytes; To Normal or No Change	7 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Eosinophils;To Low	6 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Leukocytes; To High	1 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	MCV; To Low	1 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Ret/Ery;To High	0 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Basophils; To Low	0 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Basophils; To High	0 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Eosinophils;To Low	3 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Eosinophils;To High	1 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	MCH; To Low	0 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	MCHC;To Low	0 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	MCHC; To Normal or No Change	4 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	MCHC; To High	0 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	MCV; To Low	0 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	MCV; To Normal or No Change	4 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Erythrocytes; To Low	0 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Basophils; To Normal or No Change	4 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Eosinophils; To Normal or No Change	0 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	MCH; To Normal or No Change	4 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	MCH; To High	0 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	MCV; To High	0 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Erythrocytes; To Normal or No Change	3 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Erythrocytes; To High	1 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Hematocrit; To Low	0 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Hematocrit; To Normal or No Change	4 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Hematocrit; To High	0 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Hgb; To Low	0 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Hgb; To Normal or No Change	4 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Hgb; To High	0 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Leukocytes; To Low	1 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Leukocytes; To Normal or No Change	2 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Leukocytes; To High	1 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Lymphocytes; To Low	0 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Lymphocytes; To Normal or No Change	2 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Lymphocytes; To High	2 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Monocytes; To Low	1 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Monocytes; To Normal or No Change	3 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Monocytes; To High	0 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Neutrophils; To Low	2 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Neutrophils; To Normal or No Change	1 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Neutrophils; To High	1 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Platelets; To Low	0 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Platelets; To Normal or No Change	4 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Platelets; To High	0 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Ret/Ery; To Low	1 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B	Ret/Ery; To Normal or No Change	3 Participants

Primary

Number of Participants With on Treatment Serious Adverse Events (SAEs) and Non-SAEs for Part B

An AE is any untoward medical occurrence in a participant or clinical investigation participant, temporally associated with the use of a medicinal product, whether or not considered related to the medicinal product. Any untoward event resulting in death, life threatening, requires hospitalization or prolongation of existing hospitalization, results in disability/incapacity, congenital anomaly/birth defect, any other situation according to medical or scientific judgment or all events of possible drug-induced liver injury with hyperbilirubinemia are to be categorized as SAE. On-treatment SAEs and non-SAEs are defined as events occurring from the first Part B dose until 28 days following the last Part B dose. Safety Population includes all participants who received at least one dose of mepolizumab beginning at Visit 9.

Time frame: From Week 20 and up to Week 72

Population: Safety Population

Arm	Measure	Group	Value (NUMBER)
Part A: Mepolizumab SC	Number of Participants With on Treatment Serious Adverse Events (SAEs) and Non-SAEs for Part B	Any SAE	4 Participants
Part A: Mepolizumab SC	Number of Participants With on Treatment Serious Adverse Events (SAEs) and Non-SAEs for Part B	Any Non-SAE	15 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With on Treatment Serious Adverse Events (SAEs) and Non-SAEs for Part B	Any SAE	2 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With on Treatment Serious Adverse Events (SAEs) and Non-SAEs for Part B	Any Non-SAE	8 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With on Treatment Serious Adverse Events (SAEs) and Non-SAEs for Part B	Any SAE	1 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With on Treatment Serious Adverse Events (SAEs) and Non-SAEs for Part B	Any Non-SAE	4 Participants

Primary

Number of Participants With Positive Anti-mepolizumab Binding Antibodies and Neutralizing Antibodies Response for Part B

Blood sample were collected for the determination of anti-mepolizumab binding antibodies and neutralizing antibodies response in Part B at Weeks 44, 68 and 80 prior to study treatment administration. Participant was considered 'Positive' if they had at least one positive post-Baseline anti-drug antibody assay result. All Part B visits (including scheduled and unscheduled) post-Baseline were considered for Any-time Post-Baseline visit derivation. The number of participants with positive anti-mepolizumab binding antibodies and neutralizing antibodies response at Any Time Post Baseline has been presented. The neutralizing antibodies response results only presented for participants with positive anti-drug antibody assay.

Time frame: From Week 20 and up to Week 80

Population: Safety Population

Arm	Measure	Group	Value (NUMBER)
Part A: Mepolizumab SC	Number of Participants With Positive Anti-mepolizumab Binding Antibodies and Neutralizing Antibodies Response for Part B	Anti-drug antibody	0 Participants
Part A: Mepolizumab SC	Number of Participants With Positive Anti-mepolizumab Binding Antibodies and Neutralizing Antibodies Response for Part B	Neutralizing antibody	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Positive Anti-mepolizumab Binding Antibodies and Neutralizing Antibodies Response for Part B	Anti-drug antibody	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Positive Anti-mepolizumab Binding Antibodies and Neutralizing Antibodies Response for Part B	Neutralizing antibody	0 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Positive Anti-mepolizumab Binding Antibodies and Neutralizing Antibodies Response for Part B	Anti-drug antibody	0 Participants
Part B: Mepolizumab 40/100 mg SC	Number of Participants With Positive Anti-mepolizumab Binding Antibodies and Neutralizing Antibodies Response for Part B	Neutralizing antibody	0 Participants

Primary

Plasma Apparent Clearance (CL/F) of Mepolizumab in Part A

PK of mepolizumab was evaluated in participants using CL/F. PK samples were collected at pre-dose on Weeks 4 and 8; and at Weeks 9, 12, 16 and 20 post-dose. CL was evaluated by population PK methods and mean and standard error from the final model has been tabulated. Estimates have been presented from the final model centered to mean bodyweights of 27 kg, 50 kg and 70 kg. Note the average bodyweight of 70kg (mean body weight observed in adults) was not investigated in the study.

Time frame: Pre-dose on Weeks 4 and 8; Weeks 9, 12, 16 and 20 post-dose

Population: PK Population

Arm	Measure	Group	Value (MEAN)	Dispersion
Part A: Mepolizumab SC	Plasma Apparent Clearance (CL/F) of Mepolizumab in Part A	70 kg	0.1968 Liter (L) per day	Standard Error 0.01618
Part A: Mepolizumab SC	Plasma Apparent Clearance (CL/F) of Mepolizumab in Part A	50 kg	0.1481 Liter (L) per day	Standard Error 0.007874
Part A: Mepolizumab SC	Plasma Apparent Clearance (CL/F) of Mepolizumab in Part A	27 kg	0.08803 Liter (L) per day	Standard Error 0.003078

Primary

Ratio to Baseline in Absolute Blood Eosinophil Count at Week 12 for Part A

PD of mepolizumab was evaluated in participants using ratio to Baseline in absolute blood eosinophil count. Blood samples were collected at indicated time points. Baseline was defined as the latest value recorded prior to the first dose of mepolizumab. Ratio to Baseline was calculated as post-dose visit value/Baseline value. It was evaluated by Pharmacodynamic Eosinophils (PDe) Population which included all participants receiving at least one dose of mepolizumab beginning at Visit 2 (Week 0) and having at least one Part A blood sample evaluable for blood eosinophil count.

Time frame: Baseline and Week 12

Population: PDe Population. Only those participants with data available at specific time point were analyzed.

Arm	Measure	Value (GEOMETRIC_MEAN)
Part A: Mepolizumab SC	Ratio to Baseline in Absolute Blood Eosinophil Count at Week 12 for Part A	0.115 Ratio of eosinophils in blood
Part A: Mepolizumab 100 mg SC	Ratio to Baseline in Absolute Blood Eosinophil Count at Week 12 for Part A	0.166 Ratio of eosinophils in blood

Primary

Terminal Phase Elimination Half-life (T1/2) of Mepolizumab During Treatment Period for Part A

PK of mepolizumab was evaluated in participants using t1/2. PK samples were collected at pre-dose on Weeks 4 and 8; and at Weeks 9, 12, 16 and 20 post-dose. T1/2 was evaluated by population PK methods and mean and standard error from the final model has been tabulated. Estimates have been presented from the final model centered to mean bodyweights of 27 kg, 50 kg and 70 kg. Note the average bodyweight of 70kg (mean body weight observed in adults) was not investigated in the study.

Time frame: Pre-dose on Weeks 4 and 8; Weeks 9, 12, 16 and 20 post-dose

Population: PK Population

Arm	Measure	Group	Value (MEAN)	Dispersion
Part A: Mepolizumab SC	Terminal Phase Elimination Half-life (T1/2) of Mepolizumab During Treatment Period for Part A	50 kg	21.8420 Days	Standard Error 1.0999
Part A: Mepolizumab SC	Terminal Phase Elimination Half-life (T1/2) of Mepolizumab During Treatment Period for Part A	27 kg	23.5582 Days	Standard Error 0.8406
Part A: Mepolizumab SC	Terminal Phase Elimination Half-life (T1/2) of Mepolizumab During Treatment Period for Part A	70 kg	20.9583 Days	Standard Error 1.652

Secondary

Body Weight-adjusted Apparent Clearance of Mepolizumab for Part A

PK samples were collected at pre-dose on Weeks 4 and 8; and at Weeks 9, 12, 16 and 20 post-dose. The body weight-adjusted apparent clearance was compared between adults and participants aged 6 to 11 years old with severe eosinophilic asthma when mepolizumab was administered subcutaneously. Point estimate and 90% confidence interval (CI) for participants aged 6 to 11 years (centered to a mean bodyweight of 70 kg) was compared with the historic adult estimated body-weight adjusted clearance of 0.22 L/day, around which a proposed 80-125% interval was applied i.e. 0.18-0.28 L/day. Assuming an absolute bioavailability of 75% this corresponds to an apparent clearance of 0.29 L/day with the proposed 80% to 125% interval of 0.23 to 0.36 L/day. Note the average bodyweight of 70kg (mean body weight observed in adults) was not observed in the study.

Time frame: Pre-dose on Weeks 4 and 8; Weeks 9, 12, 16 and 20 post-dose

Population: PK Population

Arm	Measure	Group	Value (MEAN)
Part A: Mepolizumab SC	Body Weight-adjusted Apparent Clearance of Mepolizumab for Part A	Weight 70kg	0.1968 L/day
Part A: Mepolizumab SC	Body Weight-adjusted Apparent Clearance of Mepolizumab for Part A	Weight 50kg	0.1481 L/day
Part A: Mepolizumab SC	Body Weight-adjusted Apparent Clearance of Mepolizumab for Part A	Weight 27kg	0.0880 L/day

Secondary

Change From Baseline in Asthma Control Questionnaire-7 (ACQ-7) at Week 12 in Part A

ACQ-7 is a simple questionnaire to measure the adequacy of asthma control and change in asthma control which occurs either spontaneously or a result of treatment. The ACQ-7 uses a 7-point scale (0=no impairment, 6= maximum impairment for symptoms and rescue use; and 7 = category for forced expiratory volume in 1 second \[FEV1\]%). The instrument has a reported high test-retest reproducibility with an intraclass correlation coefficient =0.90. The minimally important change in score is 0.5. Baseline was defined as the latest value recorded prior to the first dose of mepolizumab. Change from Baseline was calculated as score obtained at Week 12 minus Baseline Score. Pharmacodynamic Outcome (PDo) Population included all participants who received at least one dose of mepolizumab beginning at Visit 2 and having at least one Part A assessment of pharmacodynamic outcomes.

Time frame: Baseline and Week 12

Population: PDo Population. Only those participants with data available at specific time point were analyzed.

Arm	Measure	Value (MEAN)	Dispersion
Part A: Mepolizumab SC	Change From Baseline in Asthma Control Questionnaire-7 (ACQ-7) at Week 12 in Part A	-0.414 Scores on a scale	Standard Deviation 1.1354
Part A: Mepolizumab 100 mg SC	Change From Baseline in Asthma Control Questionnaire-7 (ACQ-7) at Week 12 in Part A	0.082 Scores on a scale	Standard Deviation 1.3432

Secondary

Change From Baseline in Asthma Control Questionnaire-7 (ACQ-7) at Weeks 4,8,16 and 20 in Part A

ACQ-7 is a simple questionnaire to measure the adequacy of asthma control and change in asthma control which occurs either spontaneously or a result of treatment. The ACQ-7 uses a 7-point scale (0=no impairment, 6= maximum impairment for symptoms and rescue use; and 7=category for FEV1%). The instrument has a reported high test-retest reproducibility with an intraclass correlation coefficient =0.90. The minimally important change in score is 0.5. Baseline was defined as the latest value recorded prior to the first dose of mepolizumab. Change from Baseline was calculated as score obtained at the indicated time point minus Baseline Score. Only those participants with data available at the specified time points were analyzed (represented by n=X in the category titles).

Time frame: Baseline and Weeks 4,8,16 and 20

Population: PDo Population

Arm	Measure	Group	Value (MEAN)	Dispersion
Part A: Mepolizumab SC	Change From Baseline in Asthma Control Questionnaire-7 (ACQ-7) at Weeks 4,8,16 and 20 in Part A	Week 16, n=23, 10	-0.154 Scores on a scale	Standard Deviation 1.2336
Part A: Mepolizumab SC	Change From Baseline in Asthma Control Questionnaire-7 (ACQ-7) at Weeks 4,8,16 and 20 in Part A	Week 4, n=26, 10	-0.548 Scores on a scale	Standard Deviation 1.1351
Part A: Mepolizumab SC	Change From Baseline in Asthma Control Questionnaire-7 (ACQ-7) at Weeks 4,8,16 and 20 in Part A	Week 20, n=24, 10	-0.261 Scores on a scale	Standard Deviation 1.2303
Part A: Mepolizumab SC	Change From Baseline in Asthma Control Questionnaire-7 (ACQ-7) at Weeks 4,8,16 and 20 in Part A	Week 8, n=26, 10	-0.652 Scores on a scale	Standard Deviation 1.227
Part A: Mepolizumab 100 mg SC	Change From Baseline in Asthma Control Questionnaire-7 (ACQ-7) at Weeks 4,8,16 and 20 in Part A	Week 20, n=24, 10	-0.088 Scores on a scale	Standard Deviation 1.0632
Part A: Mepolizumab 100 mg SC	Change From Baseline in Asthma Control Questionnaire-7 (ACQ-7) at Weeks 4,8,16 and 20 in Part A	Week 8, n=26, 10	-0.302 Scores on a scale	Standard Deviation 1.2445
Part A: Mepolizumab 100 mg SC	Change From Baseline in Asthma Control Questionnaire-7 (ACQ-7) at Weeks 4,8,16 and 20 in Part A	Week 16, n=23, 10	-0.087 Scores on a scale	Standard Deviation 1.2541
Part A: Mepolizumab 100 mg SC	Change From Baseline in Asthma Control Questionnaire-7 (ACQ-7) at Weeks 4,8,16 and 20 in Part A	Week 4, n=26, 10	-0.473 Scores on a scale	Standard Deviation 0.9607

Secondary

Change From Baseline in C-ACT at Weeks 4,8,16 and 20 in Part A

The C-ACT assesses asthma control in children 4-11 years of age. The C-ACT is a 7-question, 2-part questionnaire, with items 1 to 4 were completed by the child (with assistance from a caregiver, as needed) and items 5 to 7 were completed by the caregiver. A total sum score based upon responses to all items was calculated to provide an overall measure of asthma control. The derived C-ACT score ranges from 0 (maximum impairment) to 27 (no impairment), where higher scores represent a better outcome. Baseline was defined as the latest value recorded prior to the first dose of mepolizumab. Change from Baseline was calculated as score obtained at the indicated time point minus Baseline Score. Only those participants with data available at the specified time points were analyzed (represented by n=X in the category titles).

Time frame: Baseline and Weeks 4,8,16 and 20

Population: PDo Population

Arm	Measure	Group	Value (MEAN)	Dispersion
Part A: Mepolizumab SC	Change From Baseline in C-ACT at Weeks 4,8,16 and 20 in Part A	Week 4, n=26, 10	1.8 Scores on a scale	Standard Deviation 4.19
Part A: Mepolizumab SC	Change From Baseline in C-ACT at Weeks 4,8,16 and 20 in Part A	Week 8, n=26, 10	3.0 Scores on a scale	Standard Deviation 5.77
Part A: Mepolizumab SC	Change From Baseline in C-ACT at Weeks 4,8,16 and 20 in Part A	Week 16, n=23, 10	1.5 Scores on a scale	Standard Deviation 4.62
Part A: Mepolizumab SC	Change From Baseline in C-ACT at Weeks 4,8,16 and 20 in Part A	Week 20, n=24, 10	1.0 Scores on a scale	Standard Deviation 4.23
Part A: Mepolizumab 100 mg SC	Change From Baseline in C-ACT at Weeks 4,8,16 and 20 in Part A	Week 20, n=24, 10	0.9 Scores on a scale	Standard Deviation 4.28
Part A: Mepolizumab 100 mg SC	Change From Baseline in C-ACT at Weeks 4,8,16 and 20 in Part A	Week 4, n=26, 10	2.4 Scores on a scale	Standard Deviation 4.55
Part A: Mepolizumab 100 mg SC	Change From Baseline in C-ACT at Weeks 4,8,16 and 20 in Part A	Week 16, n=23, 10	-0.7 Scores on a scale	Standard Deviation 5.19
Part A: Mepolizumab 100 mg SC	Change From Baseline in C-ACT at Weeks 4,8,16 and 20 in Part A	Week 8, n=26, 10	1.5 Scores on a scale	Standard Deviation 4.28

Secondary

Change From Baseline in Childhood Asthma Control Test (C-ACT) at Week 12 for Part A

Time frame: Baseline and Week 12

Population: PDo Population. Only those participants with data available at specific time point were analyzed.

Arm	Measure	Value (MEAN)	Dispersion
Part A: Mepolizumab SC	Change From Baseline in Childhood Asthma Control Test (C-ACT) at Week 12 for Part A	2.1 Scores on a scale	Standard Deviation 4.45
Part A: Mepolizumab 100 mg SC	Change From Baseline in Childhood Asthma Control Test (C-ACT) at Week 12 for Part A	-0.3 Scores on a scale	Standard Deviation 5.19

Secondary

Change From Baseline in Sitting Pulse Rate in Part A

Sitting pulse rate measurements was performed in Part A at indicated time points. Measurements were done pre-infusion/injection with the participant sitting, having rested in this position for at least 5 minutes before each reading. The Baseline was defined as the latest value recorded prior to the first dose of mepolizumab. Change from Baseline was defined as value at indicated time point minus Baseline value. Only those participants with data available at the specified time points were analyzed (represented by n=X in the category titles).

Time frame: Baseline and Weeks 4, 8, 9, 12, 16 and 20

Population: Safety Population

Arm	Measure	Group	Value (MEAN)	Dispersion
Part A: Mepolizumab SC	Change From Baseline in Sitting Pulse Rate in Part A	Sitting pulse rate, Week 9, n=22, 10	-2.9 Beats per minute	Standard Deviation 8.31
Part A: Mepolizumab SC	Change From Baseline in Sitting Pulse Rate in Part A	Sitting pulse rate, Week 12, n=23, 10	-0.8 Beats per minute	Standard Deviation 8.31
Part A: Mepolizumab SC	Change From Baseline in Sitting Pulse Rate in Part A	Sitting pulse rate, Week 16, n=23, 10	-0.6 Beats per minute	Standard Deviation 7.65
Part A: Mepolizumab SC	Change From Baseline in Sitting Pulse Rate in Part A	Sitting pulse rate, Week 8, n=26, 10	-3.2 Beats per minute	Standard Deviation 9.11
Part A: Mepolizumab SC	Change From Baseline in Sitting Pulse Rate in Part A	Sitting pulse rate, Week 20, n=24, 10	-3.9 Beats per minute	Standard Deviation 13.13
Part A: Mepolizumab SC	Change From Baseline in Sitting Pulse Rate in Part A	Sitting pulse rate, Week 4, n=26, 10	-4.0 Beats per minute	Standard Deviation 10.91
Part A: Mepolizumab 100 mg SC	Change From Baseline in Sitting Pulse Rate in Part A	Sitting pulse rate, Week 20, n=24, 10	1.8 Beats per minute	Standard Deviation 8.22
Part A: Mepolizumab 100 mg SC	Change From Baseline in Sitting Pulse Rate in Part A	Sitting pulse rate, Week 12, n=23, 10	-0.5 Beats per minute	Standard Deviation 10.73
Part A: Mepolizumab 100 mg SC	Change From Baseline in Sitting Pulse Rate in Part A	Sitting pulse rate, Week 4, n=26, 10	-1.1 Beats per minute	Standard Deviation 10.56
Part A: Mepolizumab 100 mg SC	Change From Baseline in Sitting Pulse Rate in Part A	Sitting pulse rate, Week 8, n=26, 10	1.8 Beats per minute	Standard Deviation 7.42
Part A: Mepolizumab 100 mg SC	Change From Baseline in Sitting Pulse Rate in Part A	Sitting pulse rate, Week 16, n=23, 10	3.5 Beats per minute	Standard Deviation 10.2
Part A: Mepolizumab 100 mg SC	Change From Baseline in Sitting Pulse Rate in Part A	Sitting pulse rate, Week 9, n=22, 10	2.3 Beats per minute	Standard Deviation 9.33

Secondary

Change From Baseline in Sitting SBP and DBP in Part A

Sitting blood pressure measurements were performed in Part A at indicated time points. Measurements were done pre-infusion/injection with the participant sitting, having rested in this position for at least 5 minutes before each reading. The Baseline was defined as the latest value recorded prior to the first dose of mepolizumab. Change from Baseline was defined as value at indicated time point minus Baseline value. Only those participants with data available at the specified time points were analyzed (represented by n=X in the category titles).

Time frame: Baseline and Weeks 4, 8, 9, 12, 16 and 20

Population: Safety Population

Arm	Measure	Group	Value (MEAN)	Dispersion
Part A: Mepolizumab SC	Change From Baseline in Sitting SBP and DBP in Part A	Sitting DBP, Week 20, , n=24, 10	0.7 mmHg	Standard Deviation 6.94
Part A: Mepolizumab SC	Change From Baseline in Sitting SBP and DBP in Part A	Sitting DBP, Week 9, , n=22, 10	1.8 mmHg	Standard Deviation 9.82
Part A: Mepolizumab SC	Change From Baseline in Sitting SBP and DBP in Part A	Sitting SBP, Week 4, n=26, 10	3.6 mmHg	Standard Deviation 9.92
Part A: Mepolizumab SC	Change From Baseline in Sitting SBP and DBP in Part A	Sitting SBP, Week 8, , n=26, 10	1.8 mmHg	Standard Deviation 8.65
Part A: Mepolizumab SC	Change From Baseline in Sitting SBP and DBP in Part A	Sitting SBP, Week 9, , n=22, 10	2.8 mmHg	Standard Deviation 10.39
Part A: Mepolizumab SC	Change From Baseline in Sitting SBP and DBP in Part A	Sitting DBP, Week 12, , n=23, 10	1.5 mmHg	Standard Deviation 8.88
Part A: Mepolizumab SC	Change From Baseline in Sitting SBP and DBP in Part A	Sitting SBP, Week 12, , n=23, 10	4.3 mmHg	Standard Deviation 9.89
Part A: Mepolizumab SC	Change From Baseline in Sitting SBP and DBP in Part A	Sitting DBP, Week 8, , n=26, 10	-0.4 mmHg	Standard Deviation 5.45
Part A: Mepolizumab SC	Change From Baseline in Sitting SBP and DBP in Part A	Sitting SBP, Week 16, , n=23, 10	4.3 mmHg	Standard Deviation 11.53
Part A: Mepolizumab SC	Change From Baseline in Sitting SBP and DBP in Part A	Sitting DBP, Week 16, , n=23, 10	0.6 mmHg	Standard Deviation 6.99
Part A: Mepolizumab SC	Change From Baseline in Sitting SBP and DBP in Part A	Sitting SBP, Week 20, , n=24, 10	5.0 mmHg	Standard Deviation 9.21
Part A: Mepolizumab SC	Change From Baseline in Sitting SBP and DBP in Part A	Sitting DBP, Week 4, n=26, 10	0.4 mmHg	Standard Deviation 5.72
Part A: Mepolizumab 100 mg SC	Change From Baseline in Sitting SBP and DBP in Part A	Sitting SBP, Week 20, , n=24, 10	1.4 mmHg	Standard Deviation 9.91
Part A: Mepolizumab 100 mg SC	Change From Baseline in Sitting SBP and DBP in Part A	Sitting DBP, Week 4, n=26, 10	2.1 mmHg	Standard Deviation 3.87
Part A: Mepolizumab 100 mg SC	Change From Baseline in Sitting SBP and DBP in Part A	Sitting DBP, Week 8, , n=26, 10	3.4 mmHg	Standard Deviation 7.59
Part A: Mepolizumab 100 mg SC	Change From Baseline in Sitting SBP and DBP in Part A	Sitting DBP, Week 9, , n=22, 10	4.9 mmHg	Standard Deviation 9.13
Part A: Mepolizumab 100 mg SC	Change From Baseline in Sitting SBP and DBP in Part A	Sitting DBP, Week 12, , n=23, 10	0.3 mmHg	Standard Deviation 9.98
Part A: Mepolizumab 100 mg SC	Change From Baseline in Sitting SBP and DBP in Part A	Sitting DBP, Week 16, , n=23, 10	3.9 mmHg	Standard Deviation 7.06
Part A: Mepolizumab 100 mg SC	Change From Baseline in Sitting SBP and DBP in Part A	Sitting DBP, Week 20, , n=24, 10	5.1 mmHg	Standard Deviation 7.03
Part A: Mepolizumab 100 mg SC	Change From Baseline in Sitting SBP and DBP in Part A	Sitting SBP, Week 8, , n=26, 10	-0.2 mmHg	Standard Deviation 6.23
Part A: Mepolizumab 100 mg SC	Change From Baseline in Sitting SBP and DBP in Part A	Sitting SBP, Week 9, , n=22, 10	-0.2 mmHg	Standard Deviation 12.04
Part A: Mepolizumab 100 mg SC	Change From Baseline in Sitting SBP and DBP in Part A	Sitting SBP, Week 12, , n=23, 10	-2.9 mmHg	Standard Deviation 11.1
Part A: Mepolizumab 100 mg SC	Change From Baseline in Sitting SBP and DBP in Part A	Sitting SBP, Week 16, , n=23, 10	-4.6 mmHg	Standard Deviation 9.94
Part A: Mepolizumab 100 mg SC	Change From Baseline in Sitting SBP and DBP in Part A	Sitting SBP, Week 4, n=26, 10	-1.9 mmHg	Standard Deviation 8.81

Secondary

Number of Participants With Abnormal Findings for Urinalysis in Part A

Urine samples were collected from participants at indicated time points for analysis of urinalysis parameters including specific gravity and pH of urine, presence of glucose, protein, blood and ketones in urine by dipstick test. Microscopic examination was performed if blood or protein was abnormal. Only those participants with data available at the specified time points were analyzed.

Time frame: Up to Week 20

Population: Safety Population

Arm	Measure	Value (NUMBER)
Part A: Mepolizumab SC	Number of Participants With Abnormal Findings for Urinalysis in Part A	5 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Abnormal Findings for Urinalysis in Part A	4 Participants

Secondary

Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A

Blood samples were collected for analysis of ALT, ALP, AST, GGT, albumin, protein, total billirubin, creatinine, direct billirubin, urate, calcium, CO2, chloride, glucose, potassium, sodium and urea. Baseline was defined as the latest value recorded prior to the first dose of mepolizumab. Change from Baseline was defined as value at indicated time point minus Baseline value. Any time post Baseline = all visits (including scheduled and unscheduled) post Baseline was considered for this visit derivation. If participant had at least one value for categories To Low and/or To High along with To Normal or No Change then participant was counted under To Low and/or To High. If participant had values which belong only to To Normal or No Change then participant was counted under To Normal or No Change only. Any Time Post-Baseline values have been presented.

Time frame: Baseline and up to Week 20

Population: Safety Population

Arm	Measure	Group	Value (NUMBER)
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Total billirubin;To Low	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	CO2;To Low	12 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Total billirubin;To High	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	CO2;To Normal or No Change	14 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Albumin;To Low	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	CO2;To High	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Creatinine;To Low	4 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Chloride;To Low	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Albumin;To Normal or No Change	22 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Chloride;To Normal or No Change	23 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Creatinine;To Normal or No Change	22 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Chloride;To High	3 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	ALT; To Normal or No chang	26 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Glucose;To Low	2 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Creatinine;To High	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Glucose;To Normal or No Change	17 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Albumin;To High	4 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Glucose;To High	7 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Direct billirubin;To Low	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Potassium;To Low	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	ALT; To High	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Potassium; To Normal or No Change	26 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Direct billirubin;To Normal or No Change	26 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Potassium;To High	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Protein;To Low	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Sodium,To Low	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Direct billirubin;To High	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Sodium;To Normal or No Change	26 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	GGT;To Normal or No Change	26 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Sodium;To High	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Urate;To Low	1 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Urea;To Low	1 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Protein;To Normal or No Change	23 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Urea;To Normal or No Change	25 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Urea;To High	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Urate;To Normal or No Change	25 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	ALT; To Low	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	AST;To Low	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Urate;To High	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	AST;To Normal or No Change	26 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Protein;To High	3 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	AST;To High	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Calcium;To Low	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	ALP;To Low	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	GGT;To High	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	ALP;To Normal or No Change	26 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Calcium;To Normal or No Change	22 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	ALP;To High	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Total billirubin;To Normal or No Change	26 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	GGT;To Low	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Calcium; To High	4 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	GGT;To Low	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Total billirubin;To Low	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Urea;To Normal or No Change	7 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	ALT; To Low	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	ALT; To Normal or No chang	10 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	GGT;To Normal or No Change	10 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	GGT;To High	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Albumin;To Normal or No Change	10 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Albumin;To High	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Protein;To Low	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Protein;To Normal or No Change	10 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Protein;To High	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Total billirubin;To Normal or No Change	10 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Total billirubin;To High	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Creatinine;To Low	1 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Creatinine;To Normal or No Change	9 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Creatinine;To High	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Direct billirubin;To Low	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Direct billirubin;To Normal or No Change	10 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Direct billirubin;To High	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Urate;To Low	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Urate;To Normal or No Change	10 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Urate;To High	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Calcium;To Low	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Calcium;To Normal or No Change	8 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Calcium; To High	2 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	CO2;To Low	3 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	CO2;To Normal or No Change	7 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	CO2;To High	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Chloride;To Low	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Chloride;To Normal or No Change	9 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Chloride;To High	1 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Glucose;To Low	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Glucose;To Normal or No Change	8 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Glucose;To High	2 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Potassium;To Low	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Potassium; To Normal or No Change	10 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Potassium;To High	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Sodium,To Low	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Sodium;To Normal or No Change	10 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Sodium;To High	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Urea;To Low	3 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Urea;To High	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	ALT; To High	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	AST;To Low	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	AST;To Normal or No Change	10 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	AST;To High	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	ALP;To Low	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	ALP;To Normal or No Change	10 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	ALP;To High	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A	Albumin;To Low	0 Participants

Secondary

Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A

Blood samples were collected for analysis of basophils, eosinophils, leukocyte, monocyte, neutrophils, lymphocyte, platelet count, MCH, MCHC, Hgb, MCV, erythrocytes, hematocrit, and Ret/Ery. The Baseline was the latest value recorded prior to the first dose of mepolizumab. Change from Baseline was defined as value at indicated time point minus Baseline value. Any time post Baseline = all visits (scheduled and unscheduled) post Baseline was considered for this visit derivation. If participant had at least one value for categories To Low and/or To High along with To Normal or No Change then participant was counted under To Low and/or To High. If participant had values which belong only to To Normal or No Change then participant was counted under To Normal or No Change only. Only those participants with data available at the specified time points were analyzed (represented by n=X in the category titles). Any Time Post-Baseline values have been presented.

Time frame: Baseline and up to Week 20

Population: Safety Population

Arm	Measure	Group	Value (NUMBER)
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Monocyte; To Normal or No Change; n=26, 10	19 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Basophils; To Normal or No Change; n=26, 10	25 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Basophils; To High; n=26,10	1 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Eosinophils; To Low; n=26, 10	15 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Eosinophils; To Normal or No Change; n=26, 10	10 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Eosinophils; To High; n=26, 10	1 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Leukocyte; To Low; n=26, 10	8 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Leukocyte; To Normal or No Change; n=26, 10	17 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Leukocyte; To High; n=26, 10	1 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Monocyte; To Low; n=26, 10	6 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Basophils; To Low; n=26, 10	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Monocyte; To High; n=26, 10	1 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Neutrophils; To Low; n=26, 10	8 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Neutrophils; To Normal or No Change; n=26, 10	16 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Neutrophils; To High; n=26, 10	2 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Lymphocyte; To Low; n=26, 10	4 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Lymphocyte; To Normal or No Change; n=26, 10	20 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Lymphocyte; To High; n=26, 10	2 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Platelet count; To Low; n=25, 10	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Platelet count; To Normal or No Change; n=25, 10	22 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Platelet count; To High; n=25, 10	3 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	MCH; To Low; n=26, 10	2 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	MCH;To Normal or No Change; n=26, 10	24 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	MCH; To High; n=26, 10	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	MCHC; To Low n=26, 10	1 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	MCHC; To Normal or No Change; n=26, 10	25 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	MCHC; To High; n=26, 10	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Hgb; To Low; n=26, 10	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Hgb; To Normal or No Change; n=26, 10	26 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Hgb; To High; n=26, 10	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	MCV; To Low; n=26, 10	2 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	MCV; To Normal or No Change; n=26, 10	24 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	MCV; To High; n=26, 10	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Erythrocytes; To Low; n=26, 10	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Erythrocytes; To Normal or No Change; n=26, 10	21 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Erythrocytes; To High; n=26, 10	5 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Hematocrit; To Low; n=26, 10	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Hematocrit; To Normal or No Change; n=26, 10	26 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Hematocrit; To High; n=26, 10	0 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Reti/Ery; To Low; n=26,10	8 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Reti/Ery;To Normal/No Change;n=26,10	15 Participants
Part A: Mepolizumab SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Ret/Ery;To High; n=26,10	3 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	MCV; To Normal or No Change; n=26, 10	10 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Basophils; To Low; n=26, 10	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	MCH; To Low; n=26, 10	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Basophils; To Normal or No Change; n=26, 10	10 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Reti/Ery; To Low; n=26,10	1 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Basophils; To High; n=26,10	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	MCH;To Normal or No Change; n=26, 10	10 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Eosinophils; To Low; n=26, 10	6 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	MCV; To High; n=26, 10	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Eosinophils; To Normal or No Change; n=26, 10	4 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	MCH; To High; n=26, 10	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Eosinophils; To High; n=26, 10	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Hematocrit; To Normal or No Change; n=26, 10	8 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Leukocyte; To Low; n=26, 10	2 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	MCHC; To Low n=26, 10	1 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Leukocyte; To Normal or No Change; n=26, 10	8 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Erythrocytes; To Low; n=26, 10	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Leukocyte; To High; n=26, 10	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	MCHC; To Normal or No Change; n=26, 10	9 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Monocyte; To Low; n=26, 10	3 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Ret/Ery;To High; n=26,10	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Monocyte; To Normal or No Change; n=26, 10	7 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	MCHC; To High; n=26, 10	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Monocyte; To High; n=26, 10	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Erythrocytes; To Normal or No Change; n=26, 10	8 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Neutrophils; To Low; n=26, 10	3 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Hgb; To Low; n=26, 10	1 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Neutrophils; To Normal or No Change; n=26, 10	7 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Hematocrit; To High; n=26, 10	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Neutrophils; To High; n=26, 10	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Hgb; To Normal or No Change; n=26, 10	9 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Lymphocyte; To Low; n=26, 10	1 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Erythrocytes; To High; n=26, 10	2 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Lymphocyte; To Normal or No Change; n=26, 10	8 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Hgb; To High; n=26, 10	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Lymphocyte; To High; n=26, 10	1 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Reti/Ery;To Normal/No Change;n=26,10	9 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Platelet count; To Low; n=25, 10	1 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	MCV; To Low; n=26, 10	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Platelet count; To Normal or No Change; n=25, 10	9 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Hematocrit; To Low; n=26, 10	2 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A	Platelet count; To High; n=25, 10	0 Participants

Secondary

Number of Participants With on Treatment SAEs and Non-SAEs in Part A

An AE is any untoward medical occurrence in a participant or clinical investigation participant, temporally associated with the use of a medicinal product, whether or not considered related to the medicinal product. Any untoward event resulting in death, life threatening, requires hospitalization or prolongation of existing hospitalization, results in disability/incapacity, congenital anomaly/birth defect, any other situation according to medical or scientific judgment or all events of possible drug-induced liver injury with hyperbilirubinemia were categorized as SAE. Participants who received any of the study treatment and had any on-treatment non-SAE or SAE (defined as events occurring from the first dose until 28 days after the last dose of mepolizumab) were considered for analysis.

Time frame: Up to Week 20

Population: Safety Population

Arm	Measure	Group	Value (NUMBER)
Part A: Mepolizumab SC	Number of Participants With on Treatment SAEs and Non-SAEs in Part A	Any non-SAE	18 Participants
Part A: Mepolizumab SC	Number of Participants With on Treatment SAEs and Non-SAEs in Part A	Any SAE	5 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With on Treatment SAEs and Non-SAEs in Part A	Any non-SAE	6 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With on Treatment SAEs and Non-SAEs in Part A	Any SAE	1 Participants

Secondary

Number of Participants With Positive Anti-mepolizumab Binding Antibodies and Neutralizing Antibodies Response in Part A

Blood sample for immunogenicity was collected for anti-mepolizumab binding antibodies and neutralizing antibodies response in Part A at indicated time points prior to study treatment administration. Number of participants with positive anti-mepolizumab binding antibodies and neutralizing antibodies response was summarized. Participant was considered 'Positive' if they had at least one positive post-baseline assay result. Any Time Post Baseline has been presented, which included all visits (including scheduled and unscheduled) post-baseline was considered for this visit derivation. Only those participants with data available at the specified time points were analyzed (represented by n=X in the category titles).

Time frame: Baseline and Weeks 16 and 20

Population: Safety Population

Arm	Measure	Group	Value (NUMBER)
Part A: Mepolizumab SC	Number of Participants With Positive Anti-mepolizumab Binding Antibodies and Neutralizing Antibodies Response in Part A	Anti-drug antibody,Any time post-baseline,n=25, 10	1 Participants
Part A: Mepolizumab SC	Number of Participants With Positive Anti-mepolizumab Binding Antibodies and Neutralizing Antibodies Response in Part A	Neutralizing antibody,Any time post-baseline,n=1,1	0 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Positive Anti-mepolizumab Binding Antibodies and Neutralizing Antibodies Response in Part A	Anti-drug antibody,Any time post-baseline,n=25, 10	1 Participants
Part A: Mepolizumab 100 mg SC	Number of Participants With Positive Anti-mepolizumab Binding Antibodies and Neutralizing Antibodies Response in Part A	Neutralizing antibody,Any time post-baseline,n=1,1	0 Participants

Secondary

Ratio to Baseline in Absolute Blood Eosinophil Count at Weeks 32, 44, 56, 68, 72 and 80 for Part B

Blood samples were collected at the indicated time points for the analysis of eosinophil count. Baseline was defined as the latest value recorded prior to the first dose of mepolizumab in Part A. Ratio to Baseline was calculated as post-dose visit value/Baseline value. The analysis was based on Pharmacodynamic (Blood Eosinophils) (PDe) Population comprised of all participants receiving at least one dose of mepolizumab beginning at Visit 9 and having at least one Part B blood sample taken for blood eosinophil count. Only those participants with data available at the specified time points were analyzed (represented by n=X in the category titles).

Time frame: Baseline and Weeks 32, 44, 56, 68, 72 and 80

Population: PDe Population

Arm	Measure	Group	Value (GEOMETRIC_MEAN)
Part A: Mepolizumab SC	Ratio to Baseline in Absolute Blood Eosinophil Count at Weeks 32, 44, 56, 68, 72 and 80 for Part B	Week 56; n= 15, 10, 4	0.149 Ratio of eosinophils in blood
Part A: Mepolizumab SC	Ratio to Baseline in Absolute Blood Eosinophil Count at Weeks 32, 44, 56, 68, 72 and 80 for Part B	Week 44; n= 15, 10, 4	0.157 Ratio of eosinophils in blood
Part A: Mepolizumab SC	Ratio to Baseline in Absolute Blood Eosinophil Count at Weeks 32, 44, 56, 68, 72 and 80 for Part B	Week 72; n = 15, 10, 4	0.148 Ratio of eosinophils in blood
Part A: Mepolizumab SC	Ratio to Baseline in Absolute Blood Eosinophil Count at Weeks 32, 44, 56, 68, 72 and 80 for Part B	Week 68; n= 14, 10, 4	0.133 Ratio of eosinophils in blood
Part A: Mepolizumab SC	Ratio to Baseline in Absolute Blood Eosinophil Count at Weeks 32, 44, 56, 68, 72 and 80 for Part B	Week 32; n= 15, 10, 4	0.161 Ratio of eosinophils in blood
Part A: Mepolizumab SC	Ratio to Baseline in Absolute Blood Eosinophil Count at Weeks 32, 44, 56, 68, 72 and 80 for Part B	Week 80; n =9, 7, 0	0.591 Ratio of eosinophils in blood
Part A: Mepolizumab 100 mg SC	Ratio to Baseline in Absolute Blood Eosinophil Count at Weeks 32, 44, 56, 68, 72 and 80 for Part B	Week 80; n =9, 7, 0	0.647 Ratio of eosinophils in blood
Part A: Mepolizumab 100 mg SC	Ratio to Baseline in Absolute Blood Eosinophil Count at Weeks 32, 44, 56, 68, 72 and 80 for Part B	Week 32; n= 15, 10, 4	0.176 Ratio of eosinophils in blood
Part A: Mepolizumab 100 mg SC	Ratio to Baseline in Absolute Blood Eosinophil Count at Weeks 32, 44, 56, 68, 72 and 80 for Part B	Week 44; n= 15, 10, 4	0.189 Ratio of eosinophils in blood
Part A: Mepolizumab 100 mg SC	Ratio to Baseline in Absolute Blood Eosinophil Count at Weeks 32, 44, 56, 68, 72 and 80 for Part B	Week 56; n= 15, 10, 4	0.172 Ratio of eosinophils in blood
Part A: Mepolizumab 100 mg SC	Ratio to Baseline in Absolute Blood Eosinophil Count at Weeks 32, 44, 56, 68, 72 and 80 for Part B	Week 68; n= 14, 10, 4	0.214 Ratio of eosinophils in blood
Part A: Mepolizumab 100 mg SC	Ratio to Baseline in Absolute Blood Eosinophil Count at Weeks 32, 44, 56, 68, 72 and 80 for Part B	Week 72; n = 15, 10, 4	0.134 Ratio of eosinophils in blood
Part B: Mepolizumab 40/100 mg SC	Ratio to Baseline in Absolute Blood Eosinophil Count at Weeks 32, 44, 56, 68, 72 and 80 for Part B	Week 56; n= 15, 10, 4	0.058 Ratio of eosinophils in blood
Part B: Mepolizumab 40/100 mg SC	Ratio to Baseline in Absolute Blood Eosinophil Count at Weeks 32, 44, 56, 68, 72 and 80 for Part B	Week 32; n= 15, 10, 4	0.072 Ratio of eosinophils in blood
Part B: Mepolizumab 40/100 mg SC	Ratio to Baseline in Absolute Blood Eosinophil Count at Weeks 32, 44, 56, 68, 72 and 80 for Part B	Week 72; n = 15, 10, 4	0.098 Ratio of eosinophils in blood
Part B: Mepolizumab 40/100 mg SC	Ratio to Baseline in Absolute Blood Eosinophil Count at Weeks 32, 44, 56, 68, 72 and 80 for Part B	Week 44; n= 15, 10, 4	0.147 Ratio of eosinophils in blood
Part B: Mepolizumab 40/100 mg SC	Ratio to Baseline in Absolute Blood Eosinophil Count at Weeks 32, 44, 56, 68, 72 and 80 for Part B	Week 68; n= 14, 10, 4	0.108 Ratio of eosinophils in blood

Source: ClinicalTrials.gov · Data processed: Mar 2, 2026

Pharmacokinetics and Pharmacodynamics of Mepolizumab Administered Subcutaneously in Children

Conditions

Keywords

Brief summary

Related papers

Interventions

Sponsors

Study design

Eligibility

Inclusion criteria

Exclusion criteria

Design outcomes

Primary

Secondary

Countries

Participant flow

Recruitment details

Pre-assignment details

Participants by arm

Withdrawals & dropouts

Baseline characteristics

Adverse events

Outcome results

Area Under Concentration Time Curve to Infinity (AUC [0-inf]) of Mepolizumab for Part A

Change From Baseline in Sitting Pulse Rate for Part B

Change From Baseline in Sitting Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) for Part B

Maximum Plasma Concentration (Cmax) of Mepolizumab for Part A

Number of Participants With Abnormal Findings for Urinalysis Parameters in Part B

Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters for Part B

Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters for Part B

Number of Participants With on Treatment Serious Adverse Events (SAEs) and Non-SAEs for Part B

Number of Participants With Positive Anti-mepolizumab Binding Antibodies and Neutralizing Antibodies Response for Part B

Plasma Apparent Clearance (CL/F) of Mepolizumab in Part A

Ratio to Baseline in Absolute Blood Eosinophil Count at Week 12 for Part A

Terminal Phase Elimination Half-life (T1/2) of Mepolizumab During Treatment Period for Part A

Body Weight-adjusted Apparent Clearance of Mepolizumab for Part A

Change From Baseline in Asthma Control Questionnaire-7 (ACQ-7) at Week 12 in Part A

Change From Baseline in Asthma Control Questionnaire-7 (ACQ-7) at Weeks 4,8,16 and 20 in Part A

Change From Baseline in C-ACT at Weeks 4,8,16 and 20 in Part A

Change From Baseline in Childhood Asthma Control Test (C-ACT) at Week 12 for Part A

Change From Baseline in Sitting Pulse Rate in Part A

Change From Baseline in Sitting SBP and DBP in Part A

Number of Participants With Abnormal Findings for Urinalysis in Part A

Number of Participants With Any Time Change From Baseline Relative to Normal Range in Clinical Chemistry Parameters in Part A

Number of Participants With Any Time Change From Baseline Relative to Normal Range in Hematology Parameters in Part A

Number of Participants With on Treatment SAEs and Non-SAEs in Part A

Number of Participants With Positive Anti-mepolizumab Binding Antibodies and Neutralizing Antibodies Response in Part A

Ratio to Baseline in Absolute Blood Eosinophil Count at Weeks 32, 44, 56, 68, 72 and 80 for Part B