Trial Outcomes & Findings for Efficacy and Safety Study of Mepolizumab in Subjects With Moderate to Severe Atopic Dermatitis (NCT NCT03055195)

Last Updated: 2020-02-25

Results Overview

The IGA is a clinical tool for assessing the current state/severity of a participant's atopic dermatitis . It is a static 5-point morphological assessment of overall disease severity determined by the investigator, sub-investigator, or trained healthcare professional with required qualifications on a scale of 0 to 4 where, 0-clear, 1-almost clear, 2-mild, 3-moderate, and 4- severe. Higher score indicates severity of disease. A responder is defined as a participant who had an IGA score of 0 or 1 and a minimum 2-grade improvement from Baseline. Number of participants with IGA score of 0 or 1 and at least a 2- grade improvement at Week 16 was presented.

Recruitment status

TERMINATED

Study phase

PHASE2

Target enrollment

34 participants

Primary outcome timeframe

Week 16

Results posted on

2020-02-25

Participant Flow

This study investigated the efficacy and safety of mepolizumab administered subcutaneously (SC) in adults with moderate to severe atopic dermatitis. A total of 34 participants were enrolled at different centers in Canada and United States.

This study was terminated early, as this study reached pre-determined futility criteria following interim analysis.

Participant milestones

Participant milestones
Measure	Placebo SC Participants received placebo (0.9 percent sodium chloride solution) SC injection administered into the upper arm, abdomen, or thigh every 4 weeks.	Mepolizumab 100 mg SC Participants received 100 milligram (mg) of Mepolizumab SC injection administered into the upper arm, abdomen, or thigh every 4 weeks.
Overall Study STARTED	16	18
Overall Study COMPLETED	4	4
Overall Study NOT COMPLETED	12	14

Reasons for withdrawal

Reasons for withdrawal
Measure	Placebo SC Participants received placebo (0.9 percent sodium chloride solution) SC injection administered into the upper arm, abdomen, or thigh every 4 weeks.	Mepolizumab 100 mg SC Participants received 100 milligram (mg) of Mepolizumab SC injection administered into the upper arm, abdomen, or thigh every 4 weeks.
Overall Study Lack of Efficacy	1	0
Overall Study Withdrawal by Subject	6	7
Overall Study Study Terminated by Sponsor	2	6
Overall Study Protocol Violation	2	1
Overall Study Physician Decision	1	0

Baseline Characteristics

Efficacy and Safety Study of Mepolizumab in Subjects With Moderate to Severe Atopic Dermatitis

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Placebo SC n=16 Participants Participants received placebo (0.9 percent sodium chloride solution) SC injection administered into the upper arm, abdomen, or thigh every 4 weeks.	Mepolizumab 100 mg SC n=18 Participants Participants received 100 milligram (mg) of Mepolizumab SC injection administered into the upper arm, abdomen, or thigh every 4 weeks.	Total n=34 Participants Total of all reporting groups
Age, Continuous	30.8 Years STANDARD_DEVIATION 9.95 • n=5 Participants	34.6 Years STANDARD_DEVIATION 13.99 • n=7 Participants	32.8 Years STANDARD_DEVIATION 12.23 • n=5 Participants
Sex: Female, Male Female	7 Participants n=5 Participants	6 Participants n=7 Participants	13 Participants n=5 Participants
Sex: Female, Male Male	9 Participants n=5 Participants	12 Participants n=7 Participants	21 Participants n=5 Participants
Race/Ethnicity, Customized Asian - Central/South Asian Heritage	1 Participants n=5 Participants	1 Participants n=7 Participants	2 Participants n=5 Participants
Race/Ethnicity, Customized Asian - East Asian Heritage	5 Participants n=5 Participants	4 Participants n=7 Participants	9 Participants n=5 Participants
Race/Ethnicity, Customized Asian - Japanese Heritage	1 Participants n=5 Participants	0 Participants n=7 Participants	1 Participants n=5 Participants
Race/Ethnicity, Customized Asian - South East Asian Heritage	2 Participants n=5 Participants	2 Participants n=7 Participants	4 Participants n=5 Participants
Race/Ethnicity, Customized Black Or African American	2 Participants n=5 Participants	1 Participants n=7 Participants	3 Participants n=5 Participants
Race/Ethnicity, Customized White - White/Caucasian/European Heritage	5 Participants n=5 Participants	10 Participants n=7 Participants	15 Participants n=5 Participants

PRIMARY outcome

Timeframe: Week 16

Population: Intent-to-Treat Population comprised of all participants who were randomized and who received at least one dose of study treatment.

Outcome measures

Outcome measures
Measure	Placebo SC n=16 Participants Participants received placebo (0.9 percent sodium chloride solution) SC injection administered into the upper arm, abdomen, or thigh every 4 weeks.	Mepolizumab 100 mg SC n=18 Participants Participants received 100 milligram (mg) of Mepolizumab SC injection administered into the upper arm, abdomen, or thigh every 4 weeks.
Number of Participants With an Investigator's Global Assessment (IGA) Score of 0 or 1 and at Least a 2- Grade Improvement at Week 16	0 Participants	2 Participants

SECONDARY outcome

Timeframe: Baseline (Day 1) and Weeks 4, 8, 12, 16 and 20

Population: Intent-to-Treat Population. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).

EASI scoring system is a standardized clinical tool for the assessment of atopic dermatitis that takes into account overall extent of the percent body surface area (% BSA) involved and severity scores for each clinical signs (erythema, induration/papulation, excoriation, and lichenification). Severity scores were graded on a 4-point scale, 0(absent) to 3(severe) for each body regions (head and neck, upper extremities, lower extremities, and trunk). The severity scores for each signs were summed for each region and multiplied by the % BSA area score and by the appropriate proportionality multiplier (for participants \>=8 years of age, 0.1 for head, 0.2 upper extremities, 0.3 for trunk and 0.4 for lower extremities) to generate a regional EASI score. The regional EASI scores were then summed to yield the final EASI score. Baseline is defined as latest pre-dose assessment. Percent change from Baseline is Post-Baseline Visit Value minus Baseline, divided by Baseline and multiplied by 100.

Outcome measures

Outcome measures
Measure	Placebo SC n=16 Participants Participants received placebo (0.9 percent sodium chloride solution) SC injection administered into the upper arm, abdomen, or thigh every 4 weeks.	Mepolizumab 100 mg SC n=18 Participants Participants received 100 milligram (mg) of Mepolizumab SC injection administered into the upper arm, abdomen, or thigh every 4 weeks.
Mean Percentage Change in Eczema Area and Severity Index (EASI) Score From Baseline to Each Study Visit Week 4, n=16, 17	-22.508 Percent change Standard Deviation 30.2511	-24.556 Percent change Standard Deviation 45.4823
Mean Percentage Change in Eczema Area and Severity Index (EASI) Score From Baseline to Each Study Visit Week 8,n=15, 16	-30.497 Percent change Standard Deviation 29.0671	-43.904 Percent change Standard Deviation 43.4749
Mean Percentage Change in Eczema Area and Severity Index (EASI) Score From Baseline to Each Study Visit Week 12, n= 11, 11	-22.372 Percent change Standard Deviation 31.7156	-42.464 Percent change Standard Deviation 49.2445
Mean Percentage Change in Eczema Area and Severity Index (EASI) Score From Baseline to Each Study Visit Week 16, n=8, 6	-32.269 Percent change Standard Deviation 27.8121	-31.921 Percent change Standard Deviation 50.0658
Mean Percentage Change in Eczema Area and Severity Index (EASI) Score From Baseline to Each Study Visit Week 20, n=4, 4	1.327 Percent change Standard Deviation 32.5577	-63.938 Percent change Standard Deviation 34.2710

SECONDARY outcome

Timeframe: Weeks 4, 8, 12, 16 and 20

Population: Intent-to-Treat Population

The IGA is a clinical tool for assessing the current state/severity of a participant's atopic dermatitis . It is a static 5-point morphological assessment of overall disease severity determined by the investigator, sub-investigator, or trained healthcare professional with required qualifications on a scale of 0 to 4 where, 0-clear, 1-almost clear, 2-mild, 3-moderate, and 4- severe. Higher score indicates severity of disease. A Responder is defined as a participant who had an IGA score of 0 or 1 and a minimum 2-grade improvement from Baseline. Participants withdrawn early from the study were assigned to be a non-responder for all weeks after withdrawal. Number of participants with IGA score of 0 or 1 and at least a 2- grade improvement at each study visit (Weeks 4, 8, 12, 16 and 20) is presented.

Outcome measures

Outcome measures
Measure	Placebo SC n=16 Participants Participants received placebo (0.9 percent sodium chloride solution) SC injection administered into the upper arm, abdomen, or thigh every 4 weeks.	Mepolizumab 100 mg SC n=18 Participants Participants received 100 milligram (mg) of Mepolizumab SC injection administered into the upper arm, abdomen, or thigh every 4 weeks.
Number of Participants With an IGA Score of 0 or 1 and at Least a 2-grade Improvement at Each Study Visit Week 4	1 Participants	1 Participants
Number of Participants With an IGA Score of 0 or 1 and at Least a 2-grade Improvement at Each Study Visit Week 8	0 Participants	2 Participants
Number of Participants With an IGA Score of 0 or 1 and at Least a 2-grade Improvement at Each Study Visit Week 12	0 Participants	2 Participants
Number of Participants With an IGA Score of 0 or 1 and at Least a 2-grade Improvement at Each Study Visit Week 16	0 Participants	2 Participants
Number of Participants With an IGA Score of 0 or 1 and at Least a 2-grade Improvement at Each Study Visit Week 20	0 Participants	1 Participants

SECONDARY outcome

Timeframe: Up to Week 20

Population: Safety Population comprised of all participants who received at least one dose of a study treatment. One participant from Placebo arm received Mepolizumab at Day 1 instead of placebo due to error.

An AE is any untoward medical occurrence in a clinical investigation participant, temporally associated with the use of a medicinal product, whether or not considered related to the medicinal product. SAE is defined as any untoward medical occurrence that, at any dose results in death, is life-threatening, requires hospitalization or prolongation of existing hospitalization, results in disability/incapacity, is a congenital anomaly/ birth defect, other situations and is associated with liver injury or impaired liver function. On-treatment AES were reported on or after treatment start date and on or before treatment stop date (plus 28 days). Number of participants with AEs, SAEs and nSAEs is presented.

Outcome measures

Outcome measures
Measure	Placebo SC n=15 Participants Participants received placebo (0.9 percent sodium chloride solution) SC injection administered into the upper arm, abdomen, or thigh every 4 weeks.	Mepolizumab 100 mg SC n=19 Participants Participants received 100 milligram (mg) of Mepolizumab SC injection administered into the upper arm, abdomen, or thigh every 4 weeks.
Number of Participants With On-treatment Adverse Events (AEs), Serious Adverse Events (SAEs) and Non-serious Adverse Events (nSAEs) Any AE	7 Participants	1 Participants
Number of Participants With On-treatment Adverse Events (AEs), Serious Adverse Events (SAEs) and Non-serious Adverse Events (nSAEs) Any SAE	0 Participants	0 Participants
Number of Participants With On-treatment Adverse Events (AEs), Serious Adverse Events (SAEs) and Non-serious Adverse Events (nSAEs) Any nSAE	7 Participants	1 Participants

SECONDARY outcome

Timeframe: Up to Week 20

Population: Safety Population. One participant from Placebo arm received Mepolizumab at Day 1 instead of placebo due to error.

Outcome measures

Outcome measures
Measure	Placebo SC n=15 Participants Participants received placebo (0.9 percent sodium chloride solution) SC injection administered into the upper arm, abdomen, or thigh every 4 weeks.	Mepolizumab 100 mg SC n=19 Participants Participants received 100 milligram (mg) of Mepolizumab SC injection administered into the upper arm, abdomen, or thigh every 4 weeks.
Number of Participants With On-treatment AEs of Special Interest Reported as Local Site Injection Reaction and Systemic Reactions Local site injection reaction	0 Participants	0 Participants
Number of Participants With On-treatment AEs of Special Interest Reported as Local Site Injection Reaction and Systemic Reactions Systemic reaction	0 Participants	0 Participants

SECONDARY outcome

Timeframe: Baseline (Day 1) and Weeks 4, 8, 12, 16 and 20

Population: Safety Population. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles). One participant from Placebo arm received Mepolizumab at Day 1 instead of placebo due to error.

Blood samples were collected to analyze the hematology parameters: Basophils, Eosinophils, Leukocytes, Lymphocytes, Monocytes, Neutrophils and Platelets. Day 1 was considered as Baseline. Change from Baseline was calculated by subtracting Baseline value from the specified time point value.

Outcome measures

SECONDARY outcome

Timeframe: Baseline (Day 1) and Weeks 4, 8, 12, 16 and 20

Blood samples were collected to analyze the hematology parameter: Erythrocytes Mean Corpuscular Hemoglobin. Day 1 was considered as Baseline. Change from Baseline was calculated by subtracting Baseline value from the specified time point value.

Outcome measures

Outcome measures
Measure	Placebo SC n=15 Participants Participants received placebo (0.9 percent sodium chloride solution) SC injection administered into the upper arm, abdomen, or thigh every 4 weeks.	Mepolizumab 100 mg SC n=19 Participants Participants received 100 milligram (mg) of Mepolizumab SC injection administered into the upper arm, abdomen, or thigh every 4 weeks.
Change From Baseline in Hematology Parameter: Erythrocytes Mean Corpuscular Hemoglobin Week 4,n=15,18	0.05 Picograms Standard Deviation 0.582	0.13 Picograms Standard Deviation 0.407
Change From Baseline in Hematology Parameter: Erythrocytes Mean Corpuscular Hemoglobin Week 8,n=12,17	-0.08 Picograms Standard Deviation 0.564	0.09 Picograms Standard Deviation 0.578
Change From Baseline in Hematology Parameter: Erythrocytes Mean Corpuscular Hemoglobin Week 12,n=10,11	0.08 Picograms Standard Deviation 0.461	0.15 Picograms Standard Deviation 0.670
Change From Baseline in Hematology Parameter: Erythrocytes Mean Corpuscular Hemoglobin Week 16,n=7,7	0.46 Picograms Standard Deviation 0.336	0.11 Picograms Standard Deviation 0.708
Change From Baseline in Hematology Parameter: Erythrocytes Mean Corpuscular Hemoglobin Week 20,n=3,4	0.33 Picograms Standard Deviation 0.252	0.55 Picograms Standard Deviation 0.926

SECONDARY outcome

Timeframe: Baseline (Day 1) and Weeks 4, 8, 12, 16 and 20

Blood samples were collected to analyze the hematology parameter: Erythrocytes Mean Corpuscular Volume. Day 1 was considered as Baseline. Change from Baseline was calculated by subtracting Baseline value from the specified time point value.

Outcome measures

Outcome measures
Measure	Placebo SC n=15 Participants Participants received placebo (0.9 percent sodium chloride solution) SC injection administered into the upper arm, abdomen, or thigh every 4 weeks.	Mepolizumab 100 mg SC n=19 Participants Participants received 100 milligram (mg) of Mepolizumab SC injection administered into the upper arm, abdomen, or thigh every 4 weeks.
Change From Baseline in Hematology Parameter: Erythrocytes Mean Corpuscular Volume Week 4,n=15,18	0.2 Femtoliter Standard Deviation 2.08	0.3 Femtoliter Standard Deviation 2.45
Change From Baseline in Hematology Parameter: Erythrocytes Mean Corpuscular Volume Week 8,n=12,17	-0.4 Femtoliter Standard Deviation 1.56	-0.4 Femtoliter Standard Deviation 2.58
Change From Baseline in Hematology Parameter: Erythrocytes Mean Corpuscular Volume Week 12,n=10,11	-1.1 Femtoliter Standard Deviation 1.60	-0.7 Femtoliter Standard Deviation 2.90
Change From Baseline in Hematology Parameter: Erythrocytes Mean Corpuscular Volume Week 16,n=7,7	-0.7 Femtoliter Standard Deviation 0.76	-1.7 Femtoliter Standard Deviation 3.25
Change From Baseline in Hematology Parameter: Erythrocytes Mean Corpuscular Volume Week 20,n=3,4	-0.3 Femtoliter Standard Deviation 1.53	0.3 Femtoliter Standard Deviation 2.63

SECONDARY outcome

Timeframe: Baseline (Day 1) and Weeks 4, 8, 12, 16 and 20

Blood samples were collected to analyze the hematology parameter: Erythrocytes. Day 1 was considered as Baseline. Change from Baseline was calculated by subtracting Baseline value from the specified time point value.

Outcome measures

Outcome measures
Measure	Placebo SC n=15 Participants Participants received placebo (0.9 percent sodium chloride solution) SC injection administered into the upper arm, abdomen, or thigh every 4 weeks.	Mepolizumab 100 mg SC n=19 Participants Participants received 100 milligram (mg) of Mepolizumab SC injection administered into the upper arm, abdomen, or thigh every 4 weeks.
Change From Baseline in Hematology Parameter: Erythrocytes Week 4, n=15,18	0.02 Trillion cells/liter (10^12 cell/L) Standard Deviation 0.262	0.01 Trillion cells/liter (10^12 cell/L) Standard Deviation 0.226
Change From Baseline in Hematology Parameter: Erythrocytes Week 8, n=12,17	0.06 Trillion cells/liter (10^12 cell/L) Standard Deviation 0.294	-0.02 Trillion cells/liter (10^12 cell/L) Standard Deviation 0.283
Change From Baseline in Hematology Parameter: Erythrocytes Week 12, n=10,11	0.08 Trillion cells/liter (10^12 cell/L) Standard Deviation 0.210	0.06 Trillion cells/liter (10^12 cell/L) Standard Deviation 0.234
Change From Baseline in Hematology Parameter: Erythrocytes Week 16, n=7,7	-0.01 Trillion cells/liter (10^12 cell/L) Standard Deviation 0.204	0.10 Trillion cells/liter (10^12 cell/L) Standard Deviation 0.153
Change From Baseline in Hematology Parameter: Erythrocytes Week 20, n=3,4	0.13 Trillion cells/liter (10^12 cell/L) Standard Deviation 0.252	0.07 Trillion cells/liter (10^12 cell/L) Standard Deviation 0.096

SECONDARY outcome

Timeframe: Baseline (Day 1) and Weeks 4, 8, 12, 16 and 20

Blood samples were collected to analyze the hematology parameter: Hematocrit. Day 1 was considered as Baseline. Change from Baseline was calculated by subtracting Baseline value from the specified time point value.

Outcome measures

Outcome measures
Measure	Placebo SC n=15 Participants Participants received placebo (0.9 percent sodium chloride solution) SC injection administered into the upper arm, abdomen, or thigh every 4 weeks.	Mepolizumab 100 mg SC n=19 Participants Participants received 100 milligram (mg) of Mepolizumab SC injection administered into the upper arm, abdomen, or thigh every 4 weeks.
Change From Baseline in Hematology Parameter: Hematocrit Week 20, n=3,4	0.0130 Percentage of red blood cells in blood Standard Deviation 0.01400	0.0082 Percentage of red blood cells in blood Standard Deviation 0.00967
Change From Baseline in Hematology Parameter: Hematocrit Week 4, n=15,18	0.0030 Percentage of red blood cells in blood Standard Deviation 0.02071	0.0021 Percentage of red blood cells in blood Standard Deviation 0.02555
Change From Baseline in Hematology Parameter: Hematocrit Week 8, n=12,17	0.0024 Percentage of red blood cells in blood Standard Deviation 0.02171	-0.0042 Percentage of red blood cells in blood Standard Deviation 0.02357
Change From Baseline in Hematology Parameter: Hematocrit Week 12, n=10,11	0.0011 Percentage of red blood cells in blood Standard Deviation 0.01813	0.0005 Percentage of red blood cells in blood Standard Deviation 0.01873
Change From Baseline in Hematology Parameter: Hematocrit Week 16, n=7,7	-0.0057 Percentage of red blood cells in blood Standard Deviation 0.01616	0.0007 Percentage of red blood cells in blood Standard Deviation 0.01701

SECONDARY outcome

Timeframe: Baseline (Day 1) and Weeks 4, 8, 12, 16 and 20

Blood samples were collected to analyze the hematology parameter: Hemoglobin. Day 1 was considered as Baseline. Change from Baseline was calculated by subtracting Baseline value from the specified time point value.

Outcome measures

Outcome measures
Measure	Placebo SC n=15 Participants Participants received placebo (0.9 percent sodium chloride solution) SC injection administered into the upper arm, abdomen, or thigh every 4 weeks.	Mepolizumab 100 mg SC n=19 Participants Participants received 100 milligram (mg) of Mepolizumab SC injection administered into the upper arm, abdomen, or thigh every 4 weeks.
Change From Baseline in Hematology Parameter: Hemoglobin Week 4, n=15,18	1.0 Grams per liter Standard Deviation 7.29	0.9 Grams per liter Standard Deviation 6.82
Change From Baseline in Hematology Parameter: Hemoglobin Week 8, n=12,17	1.0 Grams per liter Standard Deviation 7.48	0.0 Grams per liter Standard Deviation 6.76
Change From Baseline in Hematology Parameter: Hemoglobin Week 12, n=10,11	2.6 Grams per liter Standard Deviation 5.44	2.3 Grams per liter Standard Deviation 5.55
Change From Baseline in Hematology Parameter: Hemoglobin Week 16, n=7,7	1.7 Grams per liter Standard Deviation 6.32	3.7 Grams per liter Standard Deviation 4.19
Change From Baseline in Hematology Parameter: Hemoglobin Week 20, n=3,4	6.7 Grams per liter Standard Deviation 6.51	5.0 Grams per liter Standard Deviation 2.45

SECONDARY outcome

Timeframe: Baseline (Day 1) and Weeks 4, 8, 12, and 16

Blood samples were collected to analyze the chemistry parameters: ALT, ALP and AST . Day 1 was considered as Baseline. Change from Baseline was calculated by subtracting Baseline value from the specified time point value.

Outcome measures

Outcome measures
Measure	Placebo SC n=15 Participants Participants received placebo (0.9 percent sodium chloride solution) SC injection administered into the upper arm, abdomen, or thigh every 4 weeks.	Mepolizumab 100 mg SC n=19 Participants Participants received 100 milligram (mg) of Mepolizumab SC injection administered into the upper arm, abdomen, or thigh every 4 weeks.
Change From Baseline in Chemistry Parameters: Alanine Aminotransferase (ALT), Alkaline Phosphatase (ALP), Aspartate Aminotransferase (AST) ALT, Week 8, n=11,16	5.9 International units per liter (IU/L) Standard Deviation 22.31	-6.3 International units per liter (IU/L) Standard Deviation 21.96
Change From Baseline in Chemistry Parameters: Alanine Aminotransferase (ALT), Alkaline Phosphatase (ALP), Aspartate Aminotransferase (AST) ALT, Week 12, n=7,11	-2.0 International units per liter (IU/L) Standard Deviation 10.00	-3.5 International units per liter (IU/L) Standard Deviation 11.01
Change From Baseline in Chemistry Parameters: Alanine Aminotransferase (ALT), Alkaline Phosphatase (ALP), Aspartate Aminotransferase (AST) ALT, Week 16, n=5,7	2.4 International units per liter (IU/L) Standard Deviation 6.69	1.7 International units per liter (IU/L) Standard Deviation 8.40
Change From Baseline in Chemistry Parameters: Alanine Aminotransferase (ALT), Alkaline Phosphatase (ALP), Aspartate Aminotransferase (AST) ALP, Week 4, n=15,18	-2.3 International units per liter (IU/L) Standard Deviation 5.85	-1.9 International units per liter (IU/L) Standard Deviation 10.06
Change From Baseline in Chemistry Parameters: Alanine Aminotransferase (ALT), Alkaline Phosphatase (ALP), Aspartate Aminotransferase (AST) ALP, Week 8, n=11,16	0.3 International units per liter (IU/L) Standard Deviation 6.89	0.4 International units per liter (IU/L) Standard Deviation 13.86
Change From Baseline in Chemistry Parameters: Alanine Aminotransferase (ALT), Alkaline Phosphatase (ALP), Aspartate Aminotransferase (AST) ALP, Week 12, n=7,11	3.9 International units per liter (IU/L) Standard Deviation 3.85	-3.8 International units per liter (IU/L) Standard Deviation 7.43
Change From Baseline in Chemistry Parameters: Alanine Aminotransferase (ALT), Alkaline Phosphatase (ALP), Aspartate Aminotransferase (AST) ALP, Week 16, n=5,7	3.2 International units per liter (IU/L) Standard Deviation 7.26	-2.6 International units per liter (IU/L) Standard Deviation 6.48
Change From Baseline in Chemistry Parameters: Alanine Aminotransferase (ALT), Alkaline Phosphatase (ALP), Aspartate Aminotransferase (AST) AST, Week 4, n=15,18	0.6 International units per liter (IU/L) Standard Deviation 4.00	-3.0 International units per liter (IU/L) Standard Deviation 11.60
Change From Baseline in Chemistry Parameters: Alanine Aminotransferase (ALT), Alkaline Phosphatase (ALP), Aspartate Aminotransferase (AST) AST, Week 8, n=11,16	-0.1 International units per liter (IU/L) Standard Deviation 8.87	-4.9 International units per liter (IU/L) Standard Deviation 11.11
Change From Baseline in Chemistry Parameters: Alanine Aminotransferase (ALT), Alkaline Phosphatase (ALP), Aspartate Aminotransferase (AST) AST, Week 12, n=7,11	-2.1 International units per liter (IU/L) Standard Deviation 5.27	-6.0 International units per liter (IU/L) Standard Deviation 13.34
Change From Baseline in Chemistry Parameters: Alanine Aminotransferase (ALT), Alkaline Phosphatase (ALP), Aspartate Aminotransferase (AST) AST, Week 16, n=5,7	0.4 International units per liter (IU/L) Standard Deviation 5.13	-1.0 International units per liter (IU/L) Standard Deviation 8.64
Change From Baseline in Chemistry Parameters: Alanine Aminotransferase (ALT), Alkaline Phosphatase (ALP), Aspartate Aminotransferase (AST) ALT, Week 4, n=15,18	1.4 International units per liter (IU/L) Standard Deviation 5.45	0.3 International units per liter (IU/L) Standard Deviation 27.10

SECONDARY outcome

Timeframe: Baseline (Day 1) and Weeks 4, 8, 12, and 16

Blood samples were collected to analyze the chemistry parameters: Albumin and Protein. Day 1 was considered as Baseline. Change from Baseline was calculated by subtracting Baseline value from the specified time point value.

Outcome measures

Outcome measures
Measure	Placebo SC n=15 Participants Participants received placebo (0.9 percent sodium chloride solution) SC injection administered into the upper arm, abdomen, or thigh every 4 weeks.	Mepolizumab 100 mg SC n=19 Participants Participants received 100 milligram (mg) of Mepolizumab SC injection administered into the upper arm, abdomen, or thigh every 4 weeks.
Change From Baseline in Chemistry Parameters: Albumin and Protein Protein, Week 16, n=5,7	-1.2 Grams per liter Standard Deviation 4.32	2.7 Grams per liter Standard Deviation 3.64
Change From Baseline in Chemistry Parameters: Albumin and Protein Albumin, Week 4, n=15,18	-0.5 Grams per liter Standard Deviation 2.75	0.3 Grams per liter Standard Deviation 3.31
Change From Baseline in Chemistry Parameters: Albumin and Protein Albumin, Week 8, n=11,16	-0.6 Grams per liter Standard Deviation 2.42	0.7 Grams per liter Standard Deviation 3.46
Change From Baseline in Chemistry Parameters: Albumin and Protein Albumin, Week 12, n=7,11	-0.6 Grams per liter Standard Deviation 2.23	1.1 Grams per liter Standard Deviation 2.77
Change From Baseline in Chemistry Parameters: Albumin and Protein Albumin, Week 16, n=5,7	-1.4 Grams per liter Standard Deviation 3.13	1.9 Grams per liter Standard Deviation 1.86
Change From Baseline in Chemistry Parameters: Albumin and Protein Protein, Week 4, n=15,18	-0.5 Grams per liter Standard Deviation 3.02	1.3 Grams per liter Standard Deviation 3.41
Change From Baseline in Chemistry Parameters: Albumin and Protein Protein, Week 8, n=11,16	0.8 Grams per liter Standard Deviation 4.02	1.6 Grams per liter Standard Deviation 4.59
Change From Baseline in Chemistry Parameters: Albumin and Protein Protein, Week 12, n=7,11	0.4 Grams per liter Standard Deviation 2.70	1.6 Grams per liter Standard Deviation 2.54

SECONDARY outcome

Timeframe: Baseline (Day 1) and Weeks 4, 8, 12, and 16

Blood samples were collected to analyze the chemistry parameters: Bilirubin, Creatinine and Direct Bilirubin. Day 1 was considered as Baseline. Change from Baseline was calculated by subtracting Baseline value from the specified time point value.

Outcome measures

Outcome measures
Measure	Placebo SC n=15 Participants Participants received placebo (0.9 percent sodium chloride solution) SC injection administered into the upper arm, abdomen, or thigh every 4 weeks.	Mepolizumab 100 mg SC n=19 Participants Participants received 100 milligram (mg) of Mepolizumab SC injection administered into the upper arm, abdomen, or thigh every 4 weeks.
Change From Baseline in Chemistry Parameters: Bilirubin, Creatinine, Direct Bilirubin Direct Bilirubin, Week 16, n=5,7	0.0 Micromoles per liter Standard Deviation 0.00	0.3 Micromoles per liter Standard Deviation 0.76
Change From Baseline in Chemistry Parameters: Bilirubin, Creatinine, Direct Bilirubin Bilirubin, Week 4, n=15,18	1.2 Micromoles per liter Standard Deviation 3.53	2.0 Micromoles per liter Standard Deviation 3.82
Change From Baseline in Chemistry Parameters: Bilirubin, Creatinine, Direct Bilirubin Bilirubin, Week 8, n=11,16	-0.4 Micromoles per liter Standard Deviation 3.32	1.6 Micromoles per liter Standard Deviation 4.27
Change From Baseline in Chemistry Parameters: Bilirubin, Creatinine, Direct Bilirubin Bilirubin, Week 12, n=7,11	-0.9 Micromoles per liter Standard Deviation 2.54	0.7 Micromoles per liter Standard Deviation 3.93
Change From Baseline in Chemistry Parameters: Bilirubin, Creatinine, Direct Bilirubin Bilirubin, Week 16, n=5,7	-1.2 Micromoles per liter Standard Deviation 1.79	2.3 Micromoles per liter Standard Deviation 5.59
Change From Baseline in Chemistry Parameters: Bilirubin, Creatinine, Direct Bilirubin Creatinine, Week 4, n=15,18	2.77 Micromoles per liter Standard Deviation 10.027	0.74 Micromoles per liter Standard Deviation 8.097
Change From Baseline in Chemistry Parameters: Bilirubin, Creatinine, Direct Bilirubin Creatinine, Week 8, n=11,16	0.74 Micromoles per liter Standard Deviation 7.250	-0.81 Micromoles per liter Standard Deviation 5.150
Change From Baseline in Chemistry Parameters: Bilirubin, Creatinine, Direct Bilirubin Creatinine, Week 12, n=7,11	0.63 Micromoles per liter Standard Deviation 2.799	1.62 Micromoles per liter Standard Deviation 6.693
Change From Baseline in Chemistry Parameters: Bilirubin, Creatinine, Direct Bilirubin Creatinine, Week 16, n=5,7	1.24 Micromoles per liter Standard Deviation 5.379	-1.63 Micromoles per liter Standard Deviation 11.755
Change From Baseline in Chemistry Parameters: Bilirubin, Creatinine, Direct Bilirubin Direct Bilirubin, Week 4, n=15,18	0.3 Micromoles per liter Standard Deviation 1.28	0.2 Micromoles per liter Standard Deviation 1.17
Change From Baseline in Chemistry Parameters: Bilirubin, Creatinine, Direct Bilirubin Direct Bilirubin, Week 8, n=11,16	-0.5 Micromoles per liter Standard Deviation 1.29	0.0 Micromoles per liter Standard Deviation 1.26
Change From Baseline in Chemistry Parameters: Bilirubin, Creatinine, Direct Bilirubin Direct Bilirubin, Week 12, n=7,11	-0.6 Micromoles per liter Standard Deviation 0.98	0.2 Micromoles per liter Standard Deviation 1.08

SECONDARY outcome

Timeframe: Baseline (Day 1) and Weeks 4, 8, 12, and 16

Blood samples were collected to analyze the chemistry parameters: Calcium, Glucose, Potassium, Sodium and Urea. Day 1 was considered as Baseline. Change from Baseline was calculated by subtracting Baseline value from the specified time point value.

Outcome measures

SECONDARY outcome

Timeframe: Up to Week 20

Population: Safety Population. Only those participants with available data at the specified time points were analyzed. One participant from Placebo arm received Mepolizumab at Day 1 instead of placebo due to error.

Blood samples were collected from participants for analysis of following hematology parameters; hematocrit, hemoglobin, leukocytes and platelets. PCI ranges were \< 0.201 or \>0.599 proportion of red blood cells in blood for hematocrit, \<71 or \>199 grams per liter for hemoglobin, \<31 or \>1499 Giga cells per liter for platelets and for leukocytes \< 1.1 Giga cells per liter. Participants were counted in the worst case category that their value changes to (low, normal or high), unless there is no change in their category. Participants with laboratory value category "To Low" and "To High" were presented. Only those parameters having worst post-Baseline PCI values were presented. Day 1 was considered as Baseline.

Outcome measures

Outcome measures
Measure	Placebo SC n=15 Participants Participants received placebo (0.9 percent sodium chloride solution) SC injection administered into the upper arm, abdomen, or thigh every 4 weeks.	Mepolizumab 100 mg SC n=18 Participants Participants received 100 milligram (mg) of Mepolizumab SC injection administered into the upper arm, abdomen, or thigh every 4 weeks.
Number of Participants With Worst Post Baseline Potential Clinical Importance (PCI) Value for Hematology Parameters Hematocrit, To Low	0 Participants	0 Participants
Number of Participants With Worst Post Baseline Potential Clinical Importance (PCI) Value for Hematology Parameters Hematocrit, To High	0 Participants	0 Participants
Number of Participants With Worst Post Baseline Potential Clinical Importance (PCI) Value for Hematology Parameters Hemoglobin, To Low	0 Participants	0 Participants
Number of Participants With Worst Post Baseline Potential Clinical Importance (PCI) Value for Hematology Parameters Hemoglobin, To High	0 Participants	0 Participants
Number of Participants With Worst Post Baseline Potential Clinical Importance (PCI) Value for Hematology Parameters Leukocytes, To Low	0 Participants	0 Participants
Number of Participants With Worst Post Baseline Potential Clinical Importance (PCI) Value for Hematology Parameters Leukocytes, To High	0 Participants	0 Participants
Number of Participants With Worst Post Baseline Potential Clinical Importance (PCI) Value for Hematology Parameters Platelets, To Low	0 Participants	0 Participants
Number of Participants With Worst Post Baseline Potential Clinical Importance (PCI) Value for Hematology Parameters Platelets, To High	0 Participants	0 Participants

SECONDARY outcome

Timeframe: Up to Week 16

Blood samples were collected from participants for analysis of following clinical chemistry parameters: ALT, Calcium, glucose, Potassium and sodium. PCI ranges were \>143 units per liter (U/L) for ALT (Age category: 3-12 years) and \>239 U/L for ALT (Age category: 13+ years), \<1.50 or \>3.24 mmol/L for calcium, \< 2.2 or \> 27.8 mmol/L for glucose, \<2.8 or \>6.5 mmoL/L for potassium , and \<120 or \>160 mmoL/L for sodium. Participants were counted in the worst case category that their value changes to (low, normal , or high), unless there is no change in their category. Participants whose laboratory value category was unchanged (e.g., High to High), or whose value became within range, were recorded in the "To within Range or No Change" category. Only those parameters having worst post-Baseline PCI values were presented. Day 1 was considered as Baseline.

Outcome measures

Outcome measures
Measure	Placebo SC n=15 Participants Participants received placebo (0.9 percent sodium chloride solution) SC injection administered into the upper arm, abdomen, or thigh every 4 weeks.	Mepolizumab 100 mg SC n=18 Participants Participants received 100 milligram (mg) of Mepolizumab SC injection administered into the upper arm, abdomen, or thigh every 4 weeks.
Number of Participants With Worst Post Baseline PCI Value for Chemistry Parameters Sodium, To High	0 Participants	0 Participants
Number of Participants With Worst Post Baseline PCI Value for Chemistry Parameters ALT, To Low	0 Participants	0 Participants
Number of Participants With Worst Post Baseline PCI Value for Chemistry Parameters ALT, To High	0 Participants	0 Participants
Number of Participants With Worst Post Baseline PCI Value for Chemistry Parameters Calcium, To Low	0 Participants	0 Participants
Number of Participants With Worst Post Baseline PCI Value for Chemistry Parameters Calcium, To High	0 Participants	0 Participants
Number of Participants With Worst Post Baseline PCI Value for Chemistry Parameters Glucose, To Low	0 Participants	0 Participants
Number of Participants With Worst Post Baseline PCI Value for Chemistry Parameters Glucose, To High	0 Participants	0 Participants
Number of Participants With Worst Post Baseline PCI Value for Chemistry Parameters Potassium, To Low	0 Participants	0 Participants
Number of Participants With Worst Post Baseline PCI Value for Chemistry Parameters Potassium, To High	0 Participants	0 Participants
Number of Participants With Worst Post Baseline PCI Value for Chemistry Parameters Sodium, To Low	0 Participants	0 Participants

SECONDARY outcome

Timeframe: Baseline (Screening) and Weeks 4, 16

Triplicate 12-lead electrocardiograms (ECG) were obtained to measure PR Interval, QRS Duration, QT Interval and QTcF Interval. Screening was considered as Baseline. Change from Baseline was calculated by subtracting Baseline value from the specified time point value.

Outcome measures

Outcome measures
Measure	Placebo SC n=15 Participants Participants received placebo (0.9 percent sodium chloride solution) SC injection administered into the upper arm, abdomen, or thigh every 4 weeks.	Mepolizumab 100 mg SC n=19 Participants Participants received 100 milligram (mg) of Mepolizumab SC injection administered into the upper arm, abdomen, or thigh every 4 weeks.
Change From Baseline in PR Interval, QRS Duration, QT Interval and QT Interval Corrected for Heart Rate According to Fridericia's Formula (QTcF) PR Interval; Week 4, n=15,18	9.1 Milliseconds Standard Deviation 9.91	-0.5 Milliseconds Standard Deviation 10.62
Change From Baseline in PR Interval, QRS Duration, QT Interval and QT Interval Corrected for Heart Rate According to Fridericia's Formula (QTcF) PR Interval; Week 16,n=12,16	-1.3 Milliseconds Standard Deviation 15.43	1.5 Milliseconds Standard Deviation 12.54
Change From Baseline in PR Interval, QRS Duration, QT Interval and QT Interval Corrected for Heart Rate According to Fridericia's Formula (QTcF) QRS duration; Week 4; n=15,18	-0.9 Milliseconds Standard Deviation 5.93	3.1 Milliseconds Standard Deviation 7.71
Change From Baseline in PR Interval, QRS Duration, QT Interval and QT Interval Corrected for Heart Rate According to Fridericia's Formula (QTcF) QRS duration; Week 16,n=12,16	-2.2 Milliseconds Standard Deviation 6.51	0.9 Milliseconds Standard Deviation 8.27
Change From Baseline in PR Interval, QRS Duration, QT Interval and QT Interval Corrected for Heart Rate According to Fridericia's Formula (QTcF) QT Interval; Week 4; n=15,18	-5.8 Milliseconds Standard Deviation 17.65	-4.7 Milliseconds Standard Deviation 16.32
Change From Baseline in PR Interval, QRS Duration, QT Interval and QT Interval Corrected for Heart Rate According to Fridericia's Formula (QTcF) QT Interval; Week 16,n=12,16	-10.8 Milliseconds Standard Deviation 18.05	-4.1 Milliseconds Standard Deviation 23.42
Change From Baseline in PR Interval, QRS Duration, QT Interval and QT Interval Corrected for Heart Rate According to Fridericia's Formula (QTcF) QTc F Interval; Week 4; n=15,18	-2.4 Milliseconds Standard Deviation 11.69	-6.4 Milliseconds Standard Deviation 14.30
Change From Baseline in PR Interval, QRS Duration, QT Interval and QT Interval Corrected for Heart Rate According to Fridericia's Formula (QTcF) QTcF Interval; Week 16,n=12,16	-2.1 Milliseconds Standard Deviation 18.20	-5.8 Milliseconds Standard Deviation 17.68

SECONDARY outcome

Timeframe: Baseline (Day 1) and Weeks 4, 8, 12, 16 and 20

SBP and DBP were measured in semi-supine position after 5 minutes rest for the participants at indicated time points. Day 1 was considered as Baseline. Change from Baseline was calculated by subtracting Baseline value from the specified time point value.

Outcome measures

Outcome measures
Measure	Placebo SC n=15 Participants Participants received placebo (0.9 percent sodium chloride solution) SC injection administered into the upper arm, abdomen, or thigh every 4 weeks.	Mepolizumab 100 mg SC n=19 Participants Participants received 100 milligram (mg) of Mepolizumab SC injection administered into the upper arm, abdomen, or thigh every 4 weeks.
Change From Baseline in Vital Signs: Diastolic Blood Pressure (DBP) and Systolic Blood Pressure (SBP) DBP, Week 4,n=15,18	1.3 Millimeters of mercury (mmHg) Standard Deviation 8.22	4.5 Millimeters of mercury (mmHg) Standard Deviation 9.73
Change From Baseline in Vital Signs: Diastolic Blood Pressure (DBP) and Systolic Blood Pressure (SBP) DBP, Week 8,n=14,17	1.6 Millimeters of mercury (mmHg) Standard Deviation 7.76	3.4 Millimeters of mercury (mmHg) Standard Deviation 7.90
Change From Baseline in Vital Signs: Diastolic Blood Pressure (DBP) and Systolic Blood Pressure (SBP) DBP, Week 12,n=10,12	-1.0 Millimeters of mercury (mmHg) Standard Deviation 5.16	3.4 Millimeters of mercury (mmHg) Standard Deviation 7.01
Change From Baseline in Vital Signs: Diastolic Blood Pressure (DBP) and Systolic Blood Pressure (SBP) DBP, Week 16,n=7,7	0.7 Millimeters of mercury (mmHg) Standard Deviation 7.30	1.9 Millimeters of mercury (mmHg) Standard Deviation 9.56
Change From Baseline in Vital Signs: Diastolic Blood Pressure (DBP) and Systolic Blood Pressure (SBP) DBP, Week 20,n=3,5	4.0 Millimeters of mercury (mmHg) Standard Deviation 0.00	5.6 Millimeters of mercury (mmHg) Standard Deviation 5.37
Change From Baseline in Vital Signs: Diastolic Blood Pressure (DBP) and Systolic Blood Pressure (SBP) SBP, Week 4,n=15,18	2.0 Millimeters of mercury (mmHg) Standard Deviation 8.99	2.6 Millimeters of mercury (mmHg) Standard Deviation 8.11
Change From Baseline in Vital Signs: Diastolic Blood Pressure (DBP) and Systolic Blood Pressure (SBP) SBP, Week 8,n=14,17	0.6 Millimeters of mercury (mmHg) Standard Deviation 8.65	4.9 Millimeters of mercury (mmHg) Standard Deviation 11.24
Change From Baseline in Vital Signs: Diastolic Blood Pressure (DBP) and Systolic Blood Pressure (SBP) SBP, Week 12,n=10,12	-0.6 Millimeters of mercury (mmHg) Standard Deviation 6.62	2.8 Millimeters of mercury (mmHg) Standard Deviation 12.22
Change From Baseline in Vital Signs: Diastolic Blood Pressure (DBP) and Systolic Blood Pressure (SBP) SBP, Week 16,n=7,7	1.1 Millimeters of mercury (mmHg) Standard Deviation 5.76	3.3 Millimeters of mercury (mmHg) Standard Deviation 10.70
Change From Baseline in Vital Signs: Diastolic Blood Pressure (DBP) and Systolic Blood Pressure (SBP) SBP, Week 20,n=3,5	0.7 Millimeters of mercury (mmHg) Standard Deviation 5.51	11.2 Millimeters of mercury (mmHg) Standard Deviation 6.14

SECONDARY outcome

Timeframe: Baseline (Day 1) and Weeks 4, 8, 12, 16 and 20

Pulse rate was measured in semi-supine position after 5 minutes rest for the participants at indicated time points. Day 1 was considered as Baseline. Change from Baseline was calculated by subtracting Baseline value from the specified time point value.

Outcome measures

Outcome measures
Measure	Placebo SC n=15 Participants Participants received placebo (0.9 percent sodium chloride solution) SC injection administered into the upper arm, abdomen, or thigh every 4 weeks.	Mepolizumab 100 mg SC n=19 Participants Participants received 100 milligram (mg) of Mepolizumab SC injection administered into the upper arm, abdomen, or thigh every 4 weeks.
Change From Baseline in Vital Signs: Pulse Rate Week 4,n=15,18	0.3 Beats per minute Standard Deviation 6.81	0.8 Beats per minute Standard Deviation 9.80
Change From Baseline in Vital Signs: Pulse Rate Week 8,n=14,17	2.4 Beats per minute Standard Deviation 9.57	-1.4 Beats per minute Standard Deviation 9.28
Change From Baseline in Vital Signs: Pulse Rate Week 12,n=10,12	0.6 Beats per minute Standard Deviation 11.27	1.0 Beats per minute Standard Deviation 12.41
Change From Baseline in Vital Signs: Pulse Rate Week 16,n=7,7	3.7 Beats per minute Standard Deviation 12.54	-1.7 Beats per minute Standard Deviation 15.68
Change From Baseline in Vital Signs: Pulse Rate Week 20,n=3,5	2.7 Beats per minute Standard Deviation 5.86	0.8 Beats per minute Standard Deviation 9.88

SECONDARY outcome

Timeframe: Baseline (Day 1) and Weeks 4, 8, 12, 16 and 20

Temperature was measured in semi-supine position after 5 minutes rest for the participants at indicated time points. Day 1 was considered as Baseline. Change from Baseline was calculated by subtracting Baseline value from the specified time point value.

Outcome measures

Outcome measures
Measure	Placebo SC n=15 Participants Participants received placebo (0.9 percent sodium chloride solution) SC injection administered into the upper arm, abdomen, or thigh every 4 weeks.	Mepolizumab 100 mg SC n=19 Participants Participants received 100 milligram (mg) of Mepolizumab SC injection administered into the upper arm, abdomen, or thigh every 4 weeks.
Change From Baseline in Vital Signs: Temperature Week 20,n=3,5	-0.17 Celsius Standard Deviation 0.153	-0.08 Celsius Standard Deviation 0.370
Change From Baseline in Vital Signs: Temperature Week 4,n=15,18	0.01 Celsius Standard Deviation 0.474	-0.02 Celsius Standard Deviation 0.345
Change From Baseline in Vital Signs: Temperature Week 8,n=14,17	0.06 Celsius Standard Deviation 0.334	0.02 Celsius Standard Deviation 0.281
Change From Baseline in Vital Signs: Temperature Week 12,n=10,12	0.06 Celsius Standard Deviation 0.357	-0.29 Celsius Standard Deviation 0.640
Change From Baseline in Vital Signs: Temperature Week 16,n=7,7	0.14 Celsius Standard Deviation 0.162	-0.27 Celsius Standard Deviation 0.309

SECONDARY outcome

Timeframe: Up to Week 20

Blood samples were collected from participants for analysis of following vital signs parameters: DBP, Pulse rate and SBP. PCI ranges were \<85 or \>160 mmHg for SBP, \<45 or \>100 mmHg for DBP and \< 40 or \> 110 beats per minute for Pulse rate. Participants were counted in the worst case category that their value changes to (low, within range or no change, or high), unless there is no change in their category. Participants with vital signs value category "To Low" and "To High" were presented. Only those parameters having worst post-Baseline PCI values are presented. Day 1 was considered as Baseline.

Outcome measures

Outcome measures
Measure	Placebo SC n=15 Participants Participants received placebo (0.9 percent sodium chloride solution) SC injection administered into the upper arm, abdomen, or thigh every 4 weeks.	Mepolizumab 100 mg SC n=18 Participants Participants received 100 milligram (mg) of Mepolizumab SC injection administered into the upper arm, abdomen, or thigh every 4 weeks.
Number of Participants With Worst Post Baseline PCI Value for Vital Signs DBP,To Low	0 Participants	0 Participants
Number of Participants With Worst Post Baseline PCI Value for Vital Signs DBP,To High	0 Participants	0 Participants
Number of Participants With Worst Post Baseline PCI Value for Vital Signs Pulse rate, To Low	0 Participants	0 Participants
Number of Participants With Worst Post Baseline PCI Value for Vital Signs Pulse rate, To High	0 Participants	1 Participants
Number of Participants With Worst Post Baseline PCI Value for Vital Signs SBP,To Low	0 Participants	0 Participants
Number of Participants With Worst Post Baseline PCI Value for Vital Signs SBP,To High	0 Participants	0 Participants

SECONDARY outcome

Timeframe: Week 4 and Week 16

Triplicate 12-lead ECG were obtained to measure ECG parameters. Abnormal findings were categorized as clinically significant (CS) and not clinically significant (NCS). Clinically significant abnormal findings are those which are not associated with the underlying disease, unless judged by the investigator to be more severe than expected for the participant's condition.

Outcome measures

Outcome measures
Measure	Placebo SC n=15 Participants Participants received placebo (0.9 percent sodium chloride solution) SC injection administered into the upper arm, abdomen, or thigh every 4 weeks.	Mepolizumab 100 mg SC n=19 Participants Participants received 100 milligram (mg) of Mepolizumab SC injection administered into the upper arm, abdomen, or thigh every 4 weeks.
Number of Participants With Abnormal Findings for ECG Parameters Week 4; CS; n=15, 18	0 Participants	0 Participants
Number of Participants With Abnormal Findings for ECG Parameters Week 4; NCS; n=15, 18	4 Participants	7 Participants
Number of Participants With Abnormal Findings for ECG Parameters Week 16; NCS; n= 12, 16	3 Participants	6 Participants
Number of Participants With Abnormal Findings for ECG Parameters Week 16; CS; n=12, 16	0 Participants	0 Participants

SECONDARY outcome

Timeframe: Up to Week 20

Blood samples were collected for the determination of anti-mepolizumab antibodies at the specified visits. The number of participants with anti-mepolizumab binding antibodies and neutralizing antibodies response at Any Time Post Baseline has been presented. Neutralizing antibodies response assay result have been only presented for participants with positive anti-drug antibody assay. Day 1 was considered as Baseline.

Outcome measures

Outcome measures
Measure	Placebo SC n=15 Participants Participants received placebo (0.9 percent sodium chloride solution) SC injection administered into the upper arm, abdomen, or thigh every 4 weeks.	Mepolizumab 100 mg SC n=19 Participants Participants received 100 milligram (mg) of Mepolizumab SC injection administered into the upper arm, abdomen, or thigh every 4 weeks.
Number of Participants With Any Time Post Baseline Anti-mepolizumab Binding Antibodies and Neutralizing Antibodies Response Binding Antibody, Negative, n=15,18	15 Participants	17 Participants
Number of Participants With Any Time Post Baseline Anti-mepolizumab Binding Antibodies and Neutralizing Antibodies Response Binding Antibody, Positive, n=15,18	0 Participants	1 Participants
Number of Participants With Any Time Post Baseline Anti-mepolizumab Binding Antibodies and Neutralizing Antibodies Response Neutralizing Antibody, Negative, n=0,1	0 Participants	1 Participants
Number of Participants With Any Time Post Baseline Anti-mepolizumab Binding Antibodies and Neutralizing Antibodies Response Neutralizing Antibody, Positive, n=0,1	0 Participants	0 Participants

Adverse Events

Placebo SC

Serious events: 0 serious events

Other events: 7 other events

Deaths: 0 deaths

Mepolizumab 100 mg SC

Serious events: 0 serious events

Other events: 1 other events

Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Other adverse events
Measure	Placebo SC n=15 participants at risk Participants received placebo (0.9 percent sodium chloride solution) SC injection administered into the upper arm, abdomen, or thigh every 4 weeks.	Mepolizumab 100 mg SC n=19 participants at risk Participants received 100 milligram (mg) of Mepolizumab SC injection administered into the upper arm, abdomen, or thigh every 4 weeks.
Infections and infestations Furuncle	6.7% 1/15 • Number of events 1 • On-treatment serious Adverse events (SAEs) and nSAEs were collected from the start of study treatment Up to 20 weeks Safety Population was used. Safety Population comprised of all participants who received at least one dose of a study treatment. One participant from Placebo arm received Mepolizumab at Day 1 instead of placebo due to error.	0.00% 0/19 • On-treatment serious Adverse events (SAEs) and nSAEs were collected from the start of study treatment Up to 20 weeks Safety Population was used. Safety Population comprised of all participants who received at least one dose of a study treatment. One participant from Placebo arm received Mepolizumab at Day 1 instead of placebo due to error.
Infections and infestations Herpes simplex	6.7% 1/15 • Number of events 1 • On-treatment serious Adverse events (SAEs) and nSAEs were collected from the start of study treatment Up to 20 weeks Safety Population was used. Safety Population comprised of all participants who received at least one dose of a study treatment. One participant from Placebo arm received Mepolizumab at Day 1 instead of placebo due to error.	0.00% 0/19 • On-treatment serious Adverse events (SAEs) and nSAEs were collected from the start of study treatment Up to 20 weeks Safety Population was used. Safety Population comprised of all participants who received at least one dose of a study treatment. One participant from Placebo arm received Mepolizumab at Day 1 instead of placebo due to error.
Infections and infestations Hordeolum	6.7% 1/15 • Number of events 1 • On-treatment serious Adverse events (SAEs) and nSAEs were collected from the start of study treatment Up to 20 weeks Safety Population was used. Safety Population comprised of all participants who received at least one dose of a study treatment. One participant from Placebo arm received Mepolizumab at Day 1 instead of placebo due to error.	0.00% 0/19 • On-treatment serious Adverse events (SAEs) and nSAEs were collected from the start of study treatment Up to 20 weeks Safety Population was used. Safety Population comprised of all participants who received at least one dose of a study treatment. One participant from Placebo arm received Mepolizumab at Day 1 instead of placebo due to error.
Infections and infestations Impetigo	0.00% 0/15 • On-treatment serious Adverse events (SAEs) and nSAEs were collected from the start of study treatment Up to 20 weeks Safety Population was used. Safety Population comprised of all participants who received at least one dose of a study treatment. One participant from Placebo arm received Mepolizumab at Day 1 instead of placebo due to error.	5.3% 1/19 • Number of events 1 • On-treatment serious Adverse events (SAEs) and nSAEs were collected from the start of study treatment Up to 20 weeks Safety Population was used. Safety Population comprised of all participants who received at least one dose of a study treatment. One participant from Placebo arm received Mepolizumab at Day 1 instead of placebo due to error.
Infections and infestations Localised infection	6.7% 1/15 • Number of events 1 • On-treatment serious Adverse events (SAEs) and nSAEs were collected from the start of study treatment Up to 20 weeks Safety Population was used. Safety Population comprised of all participants who received at least one dose of a study treatment. One participant from Placebo arm received Mepolizumab at Day 1 instead of placebo due to error.	0.00% 0/19 • On-treatment serious Adverse events (SAEs) and nSAEs were collected from the start of study treatment Up to 20 weeks Safety Population was used. Safety Population comprised of all participants who received at least one dose of a study treatment. One participant from Placebo arm received Mepolizumab at Day 1 instead of placebo due to error.
Infections and infestations Staphylococcal infection	6.7% 1/15 • Number of events 1 • On-treatment serious Adverse events (SAEs) and nSAEs were collected from the start of study treatment Up to 20 weeks Safety Population was used. Safety Population comprised of all participants who received at least one dose of a study treatment. One participant from Placebo arm received Mepolizumab at Day 1 instead of placebo due to error.	0.00% 0/19 • On-treatment serious Adverse events (SAEs) and nSAEs were collected from the start of study treatment Up to 20 weeks Safety Population was used. Safety Population comprised of all participants who received at least one dose of a study treatment. One participant from Placebo arm received Mepolizumab at Day 1 instead of placebo due to error.
Infections and infestations Staphylococcal skin infection	6.7% 1/15 • Number of events 1 • On-treatment serious Adverse events (SAEs) and nSAEs were collected from the start of study treatment Up to 20 weeks Safety Population was used. Safety Population comprised of all participants who received at least one dose of a study treatment. One participant from Placebo arm received Mepolizumab at Day 1 instead of placebo due to error.	0.00% 0/19 • On-treatment serious Adverse events (SAEs) and nSAEs were collected from the start of study treatment Up to 20 weeks Safety Population was used. Safety Population comprised of all participants who received at least one dose of a study treatment. One participant from Placebo arm received Mepolizumab at Day 1 instead of placebo due to error.
Infections and infestations Streptococcal infection	6.7% 1/15 • Number of events 1 • On-treatment serious Adverse events (SAEs) and nSAEs were collected from the start of study treatment Up to 20 weeks Safety Population was used. Safety Population comprised of all participants who received at least one dose of a study treatment. One participant from Placebo arm received Mepolizumab at Day 1 instead of placebo due to error.	0.00% 0/19 • On-treatment serious Adverse events (SAEs) and nSAEs were collected from the start of study treatment Up to 20 weeks Safety Population was used. Safety Population comprised of all participants who received at least one dose of a study treatment. One participant from Placebo arm received Mepolizumab at Day 1 instead of placebo due to error.
Infections and infestations Upper respiratory tract infection	6.7% 1/15 • Number of events 2 • On-treatment serious Adverse events (SAEs) and nSAEs were collected from the start of study treatment Up to 20 weeks Safety Population was used. Safety Population comprised of all participants who received at least one dose of a study treatment. One participant from Placebo arm received Mepolizumab at Day 1 instead of placebo due to error.	0.00% 0/19 • On-treatment serious Adverse events (SAEs) and nSAEs were collected from the start of study treatment Up to 20 weeks Safety Population was used. Safety Population comprised of all participants who received at least one dose of a study treatment. One participant from Placebo arm received Mepolizumab at Day 1 instead of placebo due to error.
Gastrointestinal disorders Diarrhoea	13.3% 2/15 • Number of events 2 • On-treatment serious Adverse events (SAEs) and nSAEs were collected from the start of study treatment Up to 20 weeks Safety Population was used. Safety Population comprised of all participants who received at least one dose of a study treatment. One participant from Placebo arm received Mepolizumab at Day 1 instead of placebo due to error.	0.00% 0/19 • On-treatment serious Adverse events (SAEs) and nSAEs were collected from the start of study treatment Up to 20 weeks Safety Population was used. Safety Population comprised of all participants who received at least one dose of a study treatment. One participant from Placebo arm received Mepolizumab at Day 1 instead of placebo due to error.
Musculoskeletal and connective tissue disorders Arthralgia	6.7% 1/15 • Number of events 1 • On-treatment serious Adverse events (SAEs) and nSAEs were collected from the start of study treatment Up to 20 weeks Safety Population was used. Safety Population comprised of all participants who received at least one dose of a study treatment. One participant from Placebo arm received Mepolizumab at Day 1 instead of placebo due to error.	0.00% 0/19 • On-treatment serious Adverse events (SAEs) and nSAEs were collected from the start of study treatment Up to 20 weeks Safety Population was used. Safety Population comprised of all participants who received at least one dose of a study treatment. One participant from Placebo arm received Mepolizumab at Day 1 instead of placebo due to error.
Nervous system disorders Dizziness	6.7% 1/15 • Number of events 1 • On-treatment serious Adverse events (SAEs) and nSAEs were collected from the start of study treatment Up to 20 weeks Safety Population was used. Safety Population comprised of all participants who received at least one dose of a study treatment. One participant from Placebo arm received Mepolizumab at Day 1 instead of placebo due to error.	0.00% 0/19 • On-treatment serious Adverse events (SAEs) and nSAEs were collected from the start of study treatment Up to 20 weeks Safety Population was used. Safety Population comprised of all participants who received at least one dose of a study treatment. One participant from Placebo arm received Mepolizumab at Day 1 instead of placebo due to error.
Skin and subcutaneous tissue disorders Skin plaque	6.7% 1/15 • Number of events 1 • On-treatment serious Adverse events (SAEs) and nSAEs were collected from the start of study treatment Up to 20 weeks Safety Population was used. Safety Population comprised of all participants who received at least one dose of a study treatment. One participant from Placebo arm received Mepolizumab at Day 1 instead of placebo due to error.	0.00% 0/19 • On-treatment serious Adverse events (SAEs) and nSAEs were collected from the start of study treatment Up to 20 weeks Safety Population was used. Safety Population comprised of all participants who received at least one dose of a study treatment. One participant from Placebo arm received Mepolizumab at Day 1 instead of placebo due to error.

Additional Information

GSK Response Center

GlaxoSmithKline

Phone: 866-435-7343

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee GSK agreements may vary with individual investigators, but will not prohibit any investigator from publishing. GSK supports the publication of results from all centers of a multi-center trial but requests that reports based on single-site data not precede the primary publication of the entire clinical trial.
Publication restrictions are in place

Restriction type: OTHER

Measure	Placebo SC n=15 Participants Participants received placebo (0.9 percent sodium chloride solution) SC injection administered into the upper arm, abdomen, or thigh every 4 weeks.	Mepolizumab 100 mg SC n=19 Participants Participants received 100 milligram (mg) of Mepolizumab SC injection administered into the upper arm, abdomen, or thigh every 4 weeks.
Change From Baseline in Hematology Parameters: Basophils, Eosinophils, Leukocytes, Lymphocytes, Monocytes, Neutrophils and Platelets Basophils, Week 4, n=15,17	0.000 Billion cells per liter (10^9/L) Standard Deviation 0.0146	-0.021 Billion cells per liter (10^9/L) Standard Deviation 0.0293
Change From Baseline in Hematology Parameters: Basophils, Eosinophils, Leukocytes, Lymphocytes, Monocytes, Neutrophils and Platelets Basophils, Week 8, n=12,17	0.013 Billion cells per liter (10^9/L) Standard Deviation 0.0234	-0.018 Billion cells per liter (10^9/L) Standard Deviation 0.0282
Change From Baseline in Hematology Parameters: Basophils, Eosinophils, Leukocytes, Lymphocytes, Monocytes, Neutrophils and Platelets Basophils, Week 12, n=10,11	0.007 Billion cells per liter (10^9/L) Standard Deviation 0.0164	-0.010 Billion cells per liter (10^9/L) Standard Deviation 0.0219
Change From Baseline in Hematology Parameters: Basophils, Eosinophils, Leukocytes, Lymphocytes, Monocytes, Neutrophils and Platelets Basophils, Week 16, n=7,7	-0.006 Billion cells per liter (10^9/L) Standard Deviation 0.0190	-0.001 Billion cells per liter (10^9/L) Standard Deviation 0.0195
Change From Baseline in Hematology Parameters: Basophils, Eosinophils, Leukocytes, Lymphocytes, Monocytes, Neutrophils and Platelets Basophils, Week 20, n=3,4	0.000 Billion cells per liter (10^9/L) Standard Deviation 0.0100	-0.008 Billion cells per liter (10^9/L) Standard Deviation 0.0150
Change From Baseline in Hematology Parameters: Basophils, Eosinophils, Leukocytes, Lymphocytes, Monocytes, Neutrophils and Platelets Eosinophils, Week 4, n=15,17	-0.028 Billion cells per liter (10^9/L) Standard Deviation 0.5179	-0.567 Billion cells per liter (10^9/L) Standard Deviation 0.2498
Change From Baseline in Hematology Parameters: Basophils, Eosinophils, Leukocytes, Lymphocytes, Monocytes, Neutrophils and Platelets Eosinophils, Week 8, n=12,17	-0.193 Billion cells per liter (10^9/L) Standard Deviation 0.3991	-0.601 Billion cells per liter (10^9/L) Standard Deviation 0.2820
Change From Baseline in Hematology Parameters: Basophils, Eosinophils, Leukocytes, Lymphocytes, Monocytes, Neutrophils and Platelets Eosinophils, Week 12, n=10,11	-0.086 Billion cells per liter (10^9/L) Standard Deviation 0.2866	-0.605 Billion cells per liter (10^9/L) Standard Deviation 0.3668
Change From Baseline in Hematology Parameters: Basophils, Eosinophils, Leukocytes, Lymphocytes, Monocytes, Neutrophils and Platelets Eosinophils, Week 16, n=7,7	0.000 Billion cells per liter (10^9/L) Standard Deviation 0.3354	-0.517 Billion cells per liter (10^9/L) Standard Deviation 0.4007
Change From Baseline in Hematology Parameters: Basophils, Eosinophils, Leukocytes, Lymphocytes, Monocytes, Neutrophils and Platelets Eosinophils, Week 20, n=3,4	0.173 Billion cells per liter (10^9/L) Standard Deviation 0.7247	-0.438 Billion cells per liter (10^9/L) Standard Deviation 0.3721
Change From Baseline in Hematology Parameters: Basophils, Eosinophils, Leukocytes, Lymphocytes, Monocytes, Neutrophils and Platelets Leukocytes, Week 4, n=15,17	-0.01 Billion cells per liter (10^9/L) Standard Deviation 1.307	-0.75 Billion cells per liter (10^9/L) Standard Deviation 1.471
Change From Baseline in Hematology Parameters: Basophils, Eosinophils, Leukocytes, Lymphocytes, Monocytes, Neutrophils and Platelets Leukocytes, Week 8, n=12,17	-0.23 Billion cells per liter (10^9/L) Standard Deviation 1.393	-0.77 Billion cells per liter (10^9/L) Standard Deviation 1.162
Change From Baseline in Hematology Parameters: Basophils, Eosinophils, Leukocytes, Lymphocytes, Monocytes, Neutrophils and Platelets Leukocytes, Week 12, n=10,11	0.68 Billion cells per liter (10^9/L) Standard Deviation 1.466	-0.59 Billion cells per liter (10^9/L) Standard Deviation 2.257
Change From Baseline in Hematology Parameters: Basophils, Eosinophils, Leukocytes, Lymphocytes, Monocytes, Neutrophils and Platelets Leukocytes, Week 16, n=7,7	0.37 Billion cells per liter (10^9/L) Standard Deviation 1.053	-0.44 Billion cells per liter (10^9/L) Standard Deviation 1.427
Change From Baseline in Hematology Parameters: Basophils, Eosinophils, Leukocytes, Lymphocytes, Monocytes, Neutrophils and Platelets Leukocytes, Week 20, n=3,4	-0.10 Billion cells per liter (10^9/L) Standard Deviation 0.866	-1.12 Billion cells per liter (10^9/L) Standard Deviation 1.372
Change From Baseline in Hematology Parameters: Basophils, Eosinophils, Leukocytes, Lymphocytes, Monocytes, Neutrophils and Platelets Lymphocytes, Week 4, n=15,17	0.001 Billion cells per liter (10^9/L) Standard Deviation 0.3654	-0.104 Billion cells per liter (10^9/L) Standard Deviation 0.4309
Change From Baseline in Hematology Parameters: Basophils, Eosinophils, Leukocytes, Lymphocytes, Monocytes, Neutrophils and Platelets Lymphocytes, Week 8, n=12,17	0.046 Billion cells per liter (10^9/L) Standard Deviation 0.5113	-0.140 Billion cells per liter (10^9/L) Standard Deviation 0.4461
Change From Baseline in Hematology Parameters: Basophils, Eosinophils, Leukocytes, Lymphocytes, Monocytes, Neutrophils and Platelets Lymphocytes, Week 12, n=10,11	-0.127 Billion cells per liter (10^9/L) Standard Deviation 0.5121	-0.057 Billion cells per liter (10^9/L) Standard Deviation 0.3453
Change From Baseline in Hematology Parameters: Basophils, Eosinophils, Leukocytes, Lymphocytes, Monocytes, Neutrophils and Platelets Lymphocytes, Week 16, n=7,7	0.409 Billion cells per liter (10^9/L) Standard Deviation 0.8914	-0.051 Billion cells per liter (10^9/L) Standard Deviation 0.2543
Change From Baseline in Hematology Parameters: Basophils, Eosinophils, Leukocytes, Lymphocytes, Monocytes, Neutrophils and Platelets Lymphocytes, Week 20, n=3,4	0.240 Billion cells per liter (10^9/L) Standard Deviation 0.4251	-0.095 Billion cells per liter (10^9/L) Standard Deviation 0.1638
Change From Baseline in Hematology Parameters: Basophils, Eosinophils, Leukocytes, Lymphocytes, Monocytes, Neutrophils and Platelets Monocytes, Week 4, n=15,17	0.057 Billion cells per liter (10^9/L) Standard Deviation 0.1247	-0.011 Billion cells per liter (10^9/L) Standard Deviation 0.1508
Change From Baseline in Hematology Parameters: Basophils, Eosinophils, Leukocytes, Lymphocytes, Monocytes, Neutrophils and Platelets Monocytes, Week 8, n=12,17	0.028 Billion cells per liter (10^9/L) Standard Deviation 0.1207	-0.090 Billion cells per liter (10^9/L) Standard Deviation 0.1634
Change From Baseline in Hematology Parameters: Basophils, Eosinophils, Leukocytes, Lymphocytes, Monocytes, Neutrophils and Platelets Monocytes, Week 12, n=10,11	0.029 Billion cells per liter (10^9/L) Standard Deviation 0.1347	-0.070 Billion cells per liter (10^9/L) Standard Deviation 0.1532
Change From Baseline in Hematology Parameters: Basophils, Eosinophils, Leukocytes, Lymphocytes, Monocytes, Neutrophils and Platelets Monocytes, Week 16, n=7,7	0.039 Billion cells per liter (10^9/L) Standard Deviation 0.1206	0.017 Billion cells per liter (10^9/L) Standard Deviation 0.0939
Change From Baseline in Hematology Parameters: Basophils, Eosinophils, Leukocytes, Lymphocytes, Monocytes, Neutrophils and Platelets Monocytes, Week 20, n=3,4	0.073 Billion cells per liter (10^9/L) Standard Deviation 0.2641	0.010 Billion cells per liter (10^9/L) Standard Deviation 0.1268
Change From Baseline in Hematology Parameters: Basophils, Eosinophils, Leukocytes, Lymphocytes, Monocytes, Neutrophils and Platelets Neutrophils, Week 4, n=15,17	-0.029 Billion cells per liter (10^9/L) Standard Deviation 1.2133	-0.062 Billion cells per liter (10^9/L) Standard Deviation 1.3958
Change From Baseline in Hematology Parameters: Basophils, Eosinophils, Leukocytes, Lymphocytes, Monocytes, Neutrophils and Platelets Neutrophils, Week 8, n=12,17	-0.103 Billion cells per liter (10^9/L) Standard Deviation 1.3031	0.068 Billion cells per liter (10^9/L) Standard Deviation 0.8773
Change From Baseline in Hematology Parameters: Basophils, Eosinophils, Leukocytes, Lymphocytes, Monocytes, Neutrophils and Platelets Neutrophils, Week 12, n=10,11	0.864 Billion cells per liter (10^9/L) Standard Deviation 1.8011	0.130 Billion cells per liter (10^9/L) Standard Deviation 1.9898
Change From Baseline in Hematology Parameters: Basophils, Eosinophils, Leukocytes, Lymphocytes, Monocytes, Neutrophils and Platelets Neutrophils, Week 16, n=7,7	-0.089 Billion cells per liter (10^9/L) Standard Deviation 1.2211	0.104 Billion cells per liter (10^9/L) Standard Deviation 1.0966
Change From Baseline in Hematology Parameters: Basophils, Eosinophils, Leukocytes, Lymphocytes, Monocytes, Neutrophils and Platelets Neutrophils, Week 20, n=3,4	-0.577 Billion cells per liter (10^9/L) Standard Deviation 0.5387	-0.587 Billion cells per liter (10^9/L) Standard Deviation 1.3189
Change From Baseline in Hematology Parameters: Basophils, Eosinophils, Leukocytes, Lymphocytes, Monocytes, Neutrophils and Platelets Platelets, Week 4, n=15,18	2.6 Billion cells per liter (10^9/L) Standard Deviation 30.86	-4.8 Billion cells per liter (10^9/L) Standard Deviation 35.02
Change From Baseline in Hematology Parameters: Basophils, Eosinophils, Leukocytes, Lymphocytes, Monocytes, Neutrophils and Platelets Platelets, Week 8, n=12,17	1.3 Billion cells per liter (10^9/L) Standard Deviation 45.31	7.5 Billion cells per liter (10^9/L) Standard Deviation 36.83
Change From Baseline in Hematology Parameters: Basophils, Eosinophils, Leukocytes, Lymphocytes, Monocytes, Neutrophils and Platelets Platelets, Week 12, n=10,11	-4.5 Billion cells per liter (10^9/L) Standard Deviation 36.92	-16.8 Billion cells per liter (10^9/L) Standard Deviation 23.34
Change From Baseline in Hematology Parameters: Basophils, Eosinophils, Leukocytes, Lymphocytes, Monocytes, Neutrophils and Platelets Platelets, Week 16, n=7,7	1.4 Billion cells per liter (10^9/L) Standard Deviation 29.73	-27.7 Billion cells per liter (10^9/L) Standard Deviation 38.87
Change From Baseline in Hematology Parameters: Basophils, Eosinophils, Leukocytes, Lymphocytes, Monocytes, Neutrophils and Platelets Platelets, Week 20, n=3,4	11.3 Billion cells per liter (10^9/L) Standard Deviation 15.57	-14.0 Billion cells per liter (10^9/L) Standard Deviation 35.07

Measure	Placebo SC n=15 Participants Participants received placebo (0.9 percent sodium chloride solution) SC injection administered into the upper arm, abdomen, or thigh every 4 weeks.	Mepolizumab 100 mg SC n=19 Participants Participants received 100 milligram (mg) of Mepolizumab SC injection administered into the upper arm, abdomen, or thigh every 4 weeks.
Change From Baseline in Chemistry Parameters: Calcium, Glucose, Potassium, Sodium and Urea Urea, Week 8, n=11,16	0.41 Millimoles per liter (mmol/L) Standard Deviation 1.114	-0.78 Millimoles per liter (mmol/L) Standard Deviation 1.722
Change From Baseline in Chemistry Parameters: Calcium, Glucose, Potassium, Sodium and Urea Calcium, Week 4, n=15,18	-0.003 Millimoles per liter (mmol/L) Standard Deviation 0.0692	-0.004 Millimoles per liter (mmol/L) Standard Deviation 0.1130
Change From Baseline in Chemistry Parameters: Calcium, Glucose, Potassium, Sodium and Urea Calcium, Week 8, n=11,16	0.007 Millimoles per liter (mmol/L) Standard Deviation 0.1093	0.001 Millimoles per liter (mmol/L) Standard Deviation 0.1097
Change From Baseline in Chemistry Parameters: Calcium, Glucose, Potassium, Sodium and Urea Calcium, Week 12, n=7,11	0.031 Millimoles per liter (mmol/L) Standard Deviation 0.1232	-0.005 Millimoles per liter (mmol/L) Standard Deviation 0.1110
Change From Baseline in Chemistry Parameters: Calcium, Glucose, Potassium, Sodium and Urea Calcium, Week 16, n=5,7	-0.076 Millimoles per liter (mmol/L) Standard Deviation 0.1126	0.043 Millimoles per liter (mmol/L) Standard Deviation 0.0941
Change From Baseline in Chemistry Parameters: Calcium, Glucose, Potassium, Sodium and Urea Glucose, Week 4, n=15,18	-0.13 Millimoles per liter (mmol/L) Standard Deviation 0.841	0.20 Millimoles per liter (mmol/L) Standard Deviation 0.707
Change From Baseline in Chemistry Parameters: Calcium, Glucose, Potassium, Sodium and Urea Glucose, Week 8, n=11,16	-0.56 Millimoles per liter (mmol/L) Standard Deviation 1.267	0.53 Millimoles per liter (mmol/L) Standard Deviation 0.846
Change From Baseline in Chemistry Parameters: Calcium, Glucose, Potassium, Sodium and Urea Glucose, Week 12, n=7,11	0.90 Millimoles per liter (mmol/L) Standard Deviation 2.653	0.14 Millimoles per liter (mmol/L) Standard Deviation 1.002
Change From Baseline in Chemistry Parameters: Calcium, Glucose, Potassium, Sodium and Urea Glucose, Week 16, n=5,7	0.26 Millimoles per liter (mmol/L) Standard Deviation 0.783	0.21 Millimoles per liter (mmol/L) Standard Deviation 0.857
Change From Baseline in Chemistry Parameters: Calcium, Glucose, Potassium, Sodium and Urea Potassium, Week 4, n=15,18	-0.02 Millimoles per liter (mmol/L) Standard Deviation 0.265	-0.01 Millimoles per liter (mmol/L) Standard Deviation 0.252
Change From Baseline in Chemistry Parameters: Calcium, Glucose, Potassium, Sodium and Urea Potassium, Week 8, n=11,16	0.07 Millimoles per liter (mmol/L) Standard Deviation 0.290	-0.03 Millimoles per liter (mmol/L) Standard Deviation 0.272
Change From Baseline in Chemistry Parameters: Calcium, Glucose, Potassium, Sodium and Urea Potassium, Week 12, n=7,11	0.19 Millimoles per liter (mmol/L) Standard Deviation 0.254	-0.06 Millimoles per liter (mmol/L) Standard Deviation 0.191
Change From Baseline in Chemistry Parameters: Calcium, Glucose, Potassium, Sodium and Urea Potassium, Week 16, n=5,7	0.04 Millimoles per liter (mmol/L) Standard Deviation 0.288	-0.09 Millimoles per liter (mmol/L) Standard Deviation 0.363
Change From Baseline in Chemistry Parameters: Calcium, Glucose, Potassium, Sodium and Urea Sodium, Week 4, n=15,18	0.3 Millimoles per liter (mmol/L) Standard Deviation 1.88	-0.9 Millimoles per liter (mmol/L) Standard Deviation 1.94
Change From Baseline in Chemistry Parameters: Calcium, Glucose, Potassium, Sodium and Urea Sodium, Week 8, n=11,16	1.0 Millimoles per liter (mmol/L) Standard Deviation 1.34	-0.2 Millimoles per liter (mmol/L) Standard Deviation 1.76
Change From Baseline in Chemistry Parameters: Calcium, Glucose, Potassium, Sodium and Urea Sodium, Week 12, n=7,11	0.0 Millimoles per liter (mmol/L) Standard Deviation 1.83	0.1 Millimoles per liter (mmol/L) Standard Deviation 1.04
Change From Baseline in Chemistry Parameters: Calcium, Glucose, Potassium, Sodium and Urea Sodium, Week 16, n=5,7	-1.2 Millimoles per liter (mmol/L) Standard Deviation 1.30	0.4 Millimoles per liter (mmol/L) Standard Deviation 2.30
Change From Baseline in Chemistry Parameters: Calcium, Glucose, Potassium, Sodium and Urea Urea, Week 4, n=15,18	0.23 Millimoles per liter (mmol/L) Standard Deviation 1.015	-0.25 Millimoles per liter (mmol/L) Standard Deviation 1.204
Change From Baseline in Chemistry Parameters: Calcium, Glucose, Potassium, Sodium and Urea Urea, Week 12, n=7,11	-0.07 Millimoles per liter (mmol/L) Standard Deviation 1.813	-0.59 Millimoles per liter (mmol/L) Standard Deviation 1.998
Change From Baseline in Chemistry Parameters: Calcium, Glucose, Potassium, Sodium and Urea Urea, Week 16, n=5,7	0.30 Millimoles per liter (mmol/L) Standard Deviation 1.304	-0.50 Millimoles per liter (mmol/L) Standard Deviation 2.255