Trial Outcomes & Findings for Efficacy and Safety of Mepolizumab in Adults With Chronic Rhinosinusitis With Nasal Polyps (CRSwNP)/ Eosinophilic Chronic Rhinosinusitis (ECRS) (NCT NCT04607005)

Results Overview

Total endoscopic nasal polyp score is collected at clinical visits. Independent reviewers, blinded to treatment, reviewed image recordings of nasal endoscopies to determine total endoscopic NP score based on NP size. The right and left nostrils were scored from 0 to 4 (0 = No polyps; 1 = Small polyps in the middle meatus not reaching below the inferior border of the middle concha; 2 = Polyps reaching below the lower border of the middle turbinate; 3 = Large polyps reaching the lower border of the inferior turbinate or polyps medial to the middle concha; and 4 = Large polyps causing complete obstruction/congestion of the inferior meatus). The total score is the sum of the right and left nostril scores and ranges from 0 to 8 (calculated by summing the scores \[0 to 4\] in each nostril), higher scores indicate worse status. Baseline was defined as Day 1 value. Change from Baseline = Post-baseline value minus Baseline value.

Recruitment status

COMPLETED

Study phase

PHASE3

Target enrollment

169 participants

Primary outcome timeframe

Baseline (Day 1) up to week 52

Results posted on

2024-11-25

Participant Flow

GlaxoSmithKline (GSK) was informed of suspected Good Clinical Practices (GCP) violations in Medipharma, a Japanese site management organization (SMO) which provided site management services to 2 sites for this study, at which 6 participants were enrolled (4 participants in Mepolizumab + Standard of care (SOC) arm and 2 participants in Placebo + SOC arm). Analysis was performed on two sets of population based on GCP non-compliance (Intent to treat (ITT) and ITT excluding Non-GCP Site).

A total of 169 participants were randomized in a ratio of 1:1 to receive a single dose of 100 milligrams per millilitre (mg/mL) mepolizumab or placebo subcutaneously (SC) every 4 weeks during the 52-week of treatment period.

Participant milestones

Participant milestones
Measure	Mepolizumab Participants received one dose of 100 mg/mL mepolizumab subcutaneous (SC) on top of Standard of Care (SoC) every 4 weeks during the 52-week treatment period.	Placebo Participants received one dose of matching placebo via SC route on top of SoC, every 4 weeks during the 52-week treatment period.
Overall Study STARTED	84	85
Overall Study Intent-to-Treat Population	84	85
Overall Study Intent-to-Treat Population Excluding Non GCP Sites	80	83
Overall Study COMPLETED	78	69
Overall Study NOT COMPLETED	6	16

Reasons for withdrawal

Reasons for withdrawal
Measure	Mepolizumab Participants received one dose of 100 mg/mL mepolizumab subcutaneous (SC) on top of Standard of Care (SoC) every 4 weeks during the 52-week treatment period.	Placebo Participants received one dose of matching placebo via SC route on top of SoC, every 4 weeks during the 52-week treatment period.
Overall Study Adverse Event	0	1
Overall Study Lack of Efficacy	1	6
Overall Study Withdrawal by Subject	4	9
Overall Study Participant reached protocol-defined stopping criteria	1	0

Baseline Characteristics

Efficacy and Safety of Mepolizumab in Adults With Chronic Rhinosinusitis With Nasal Polyps (CRSwNP)/ Eosinophilic Chronic Rhinosinusitis (ECRS)

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Mepolizumab n=84 Participants Participants received one dose of 100 mg/mL mepolizumab subcutaneous (SC) on top of Standard of Care (SoC) every 4 weeks during the 52-week treatment period.	Placebo n=85 Participants Participants received one dose of matching placebo via SC route on top of SoC, every 4 weeks during the 52-week treatment period.	Total n=169 Participants Total of all reporting groups
Age, Continuous	52.4 YEARS STANDARD_DEVIATION 10.53 • n=5 Participants	51.8 YEARS STANDARD_DEVIATION 13.23 • n=7 Participants	52.1 YEARS STANDARD_DEVIATION 11.93 • n=5 Participants
Sex: Female, Male Female	31 Participants n=5 Participants	29 Participants n=7 Participants	60 Participants n=5 Participants
Sex: Female, Male Male	53 Participants n=5 Participants	56 Participants n=7 Participants	109 Participants n=5 Participants
Race/Ethnicity, Customized ASIAN	60 Participants n=5 Participants	61 Participants n=7 Participants	121 Participants n=5 Participants
Race/Ethnicity, Customized WHITE	24 Participants n=5 Participants	24 Participants n=7 Participants	48 Participants n=5 Participants

PRIMARY outcome

Timeframe: Baseline (Day 1) up to week 52

Population: The analysis was performed on the ITT Set (randomized participants who received at least 1 dose of study treatment) excluding participants from Medipharma managed sites. Participants were analyzed according to the treatment they were allocated at randomization. Analysis was performed using missing at random (MAR) assumption to handle missing data.

Total endoscopic nasal polyp score is collected at clinical visits. Independent reviewers, blinded to treatment, reviewed image recordings of nasal endoscopies to determine total endoscopic NP score based on NP size. The right and left nostrils were scored from 0 to 4 (0 = No polyps; 1 = Small polyps in the middle meatus not reaching below the inferior border of the middle concha; 2 = Polyps reaching below the lower border of the middle turbinate; 3 = Large polyps reaching the lower border of the inferior turbinate or polyps medial to the middle concha; and 4 = Large polyps causing complete obstruction/congestion of the inferior meatus). The total score is the sum of the right and left nostril scores and ranges from 0 to 8 (calculated by summing the scores \[0 to 4\] in each nostril), higher scores indicate worse status. Baseline was defined as Day 1 value. Change from Baseline = Post-baseline value minus Baseline value.

Outcome measures

Outcome measures
Measure	Mepolizumab n=80 Participants Participants received one dose of 100 mg/mL mepolizumab subcutaneous (SC) on top of Standard of Care (SoC) every 4 weeks during the 52-week treatment period.	Placebo n=83 Participants Participants received one dose of matching placebo via SC route on top of SoC, every 4 weeks during the 52-week treatment period.
Mean Change From Baseline in Total Endoscopic Nasal Polyps (NP) Score at Week 52 - ITT Population Excluding Medipharma Managed Sites	-0.62 Scores on a Scale Standard Error 0.164	-0.19 Scores on a Scale Standard Error 0.164

PRIMARY outcome

Timeframe: Baseline (Day 1) up to Week 52

Population: The analysis was performed on the Intent to Treat (ITT) Set that included all randomized participants who received at least 1 dose of study treatment. Participants were analyzed according to the treatment they were allocated at randomization. Analysis was performed using missing at random (MAR) assumption to handle missing data.

Total endoscopic nasal polyp score is collected at clinical visits. The assessments were performed by central video image recordings of nasal endoscopy (NE). The right and left nostrils were scored from 0 to 4 (0 = No polyps; 1 = Small polyps in the middle meatus not reaching below the inferior border of the middle concha; 2 = Polyps reaching below the lower border of the middle turbinate; 3 = Large polyps reaching the lower border of the inferior turbinate or polyps medial to the middle concha; and 4 = Large polyps causing complete obstruction/congestion of the inferior meatus). The total score is the sum of the right and left nostril scores and ranges from 0 to 8 (calculated by summing the scores \[0 to 4\] in each nostril), "0" score represents better status while "8" represents worse status. Baseline was defined as last value prior to first dose (Day 1). Change from Baseline = Post-baseline value minus Baseline value.

Outcome measures

Outcome measures
Measure	Mepolizumab n=84 Participants Participants received one dose of 100 mg/mL mepolizumab subcutaneous (SC) on top of Standard of Care (SoC) every 4 weeks during the 52-week treatment period.	Placebo n=85 Participants Participants received one dose of matching placebo via SC route on top of SoC, every 4 weeks during the 52-week treatment period.
Mean Change From Baseline in Total Endoscopic NP Score at Week 52 - Intent-to-Treat (ITT) Population	-0.65 Scores on a Scale Standard Error 0.160	-0.19 Scores on a Scale Standard Error 0.162

PRIMARY outcome

Timeframe: Baseline (Day 1) up to 4 weeks prior to week 52

Population: The analysis was performed on the ITT Set (randomized participants who received at least 1 dose of study treatment) excluding participants from Medipharma managed sites. Participants were analyzed according to the treatment they were allocated at randomization. Analysis was performed using MAR assumption to handle missing data.

Participants rated individual (nasal obstruction, nasal discharge, mucus in the throat, loss of smell, facial pain) and overall symptoms on a visual analog scale (VAS) using an electronic diary (eDiary). Captured scores ranged between 0 (none) and 100 (as bad as you can imagine), final scores derived from the electronically captured scores by dividing by 10. The final nasal obstruction VAS score ranged between 0 (none) and 10 (worst), with higher scores indicating greater disease severity. The average of daily scores in 4-weekly intervals were calculated and data is presented for Weeks 49-52. Baseline was defined as the average score from the 7 days of eDiary data collected prior to Day 1. Change from Baseline = Post-baseline value minus Baseline value.

Outcome measures

Outcome measures
Measure	Mepolizumab n=80 Participants Participants received one dose of 100 mg/mL mepolizumab subcutaneous (SC) on top of Standard of Care (SoC) every 4 weeks during the 52-week treatment period.	Placebo n=83 Participants Participants received one dose of matching placebo via SC route on top of SoC, every 4 weeks during the 52-week treatment period.
Mean Change From Baseline in Mean Nasal Obstruction Visual Analogue Scale (VAS) Score During the 4 Weeks Prior to Week 52 - ITT Population Excluding Medipharma Managed Sites	-3.23 Scores on a Scale Standard Error 0.336	-1.80 Scores on a Scale Standard Error 0.333

PRIMARY outcome

Timeframe: Baseline (Day 1) up to 4 weeks prior to week 52

Population: The analysis was performed on the ITT Set that included all randomized participants who received at least 1 dose of study treatment. Participants were analyzed according to the treatment they were allocated at randomization. Analysis was performed using MAR assumption to handle missing data.

Participants rated individual (nasal obstruction, nasal discharge, mucus in the throat, loss of smell, facial pain) and overall symptoms on a visual analog scale (VAS) using an electronic diary (eDiary). Captured scores ranged between 0 (none) and 100 (as bad as you can imagine), final scores derived from the electronically captured scores dividing by 10. The final nasal obstruction VAS score ranged between 0 and 10, with higher scores indicating greater disease severity. The average of daily scores in 4-weekly intervals were calculated and data is presented for Weeks 49-52. Baseline was defined as the average score from the 7 days of eDiary data collected prior to Day 1. Change from Baseline = Post-baseline value minus Baseline value.

Outcome measures

Outcome measures
Measure	Mepolizumab n=84 Participants Participants received one dose of 100 mg/mL mepolizumab subcutaneous (SC) on top of Standard of Care (SoC) every 4 weeks during the 52-week treatment period.	Placebo n=85 Participants Participants received one dose of matching placebo via SC route on top of SoC, every 4 weeks during the 52-week treatment period.
Mean Change From Baseline in Mean Nasal Obstruction VAS Score During the 4 Weeks Prior to Week 52 - ITT Population	-3.20 Scores on a Scale Standard Error 0.328	-1.77 Scores on a Scale Standard Error 0.331

SECONDARY outcome

Timeframe: Baseline (Day 1) up to 4 weeks prior to week 52

Population: The analysis was performed on the ITT Set (randomized participants who received at least 1 dose of study treatment) excluding participants from Medipharma managed sites. Participants were analyzed according to the treatment they were allocated at randomization. Analysis was performed using MAR assumption to handle missing data.

Participants rated individual (nasal obstruction, nasal discharge, mucus in the throat, loss of smell, facial pain) and overall symptoms on a visual analog scale using an eDiary. Captured scores ranged between 0 (none) and 100 (as bad as you can imagine), final scores derived from the electronically captured scores by dividing by 10. The final overall VAS score ranged between 0 (none) and 10 (worst), with higher scores indicating greater disease severity. The average of daily scores in 4-weekly intervals were calculated and data is presented for Weeks 49-52. Baseline was defined as the average score from the 7 days of eDiary data collected prior to Day 1. Change from Baseline = Post-baseline value minus Baseline value.

Outcome measures

Outcome measures
Measure	Mepolizumab n=80 Participants Participants received one dose of 100 mg/mL mepolizumab subcutaneous (SC) on top of Standard of Care (SoC) every 4 weeks during the 52-week treatment period.	Placebo n=83 Participants Participants received one dose of matching placebo via SC route on top of SoC, every 4 weeks during the 52-week treatment period.
Mean Change From Baseline in Mean Overall VAS Symptom Score During the 4 Weeks Prior to Week 52 - ITT Population Excluding Medipharma Managed Sites	-3.33 Scores on a Scale Standard Error 0.354	-1.80 Scores on a Scale Standard Error 0.352

SECONDARY outcome

Timeframe: Baseline (Day 1) up to 4 weeks prior to week 52

Population: The analysis was performed on the ITT Set that included all randomized participants who received at least 1 dose of study treatment. Participants were analyzed according to the treatment they were allocated at randomization. Analysis was performed using MAR assumption to handle missing data.

Participants rated individual (nasal obstruction, nasal discharge, mucus in the throat, loss of smell, facial pain) and overall symptoms on a visual analog scale using an eDiary. Captured scores ranged between 0 (none) and 100 (as bad as you can imagine), final scores derived from the electronically captured scores by dividing by 10. The final overall VAS score ranged between 0 (none) and 10 (worst), with higher scores indicating greater disease severity. The average of daily scores in 4-weekly intervals were calculated and data is presented for Weeks 49-52. Baseline was defined as the average score from the 7 days of eDiary data collected prior to Day 1. Change from Baseline = Post-baseline value minus Baseline value.

Outcome measures

Outcome measures
Measure	Mepolizumab n=84 Participants Participants received one dose of 100 mg/mL mepolizumab subcutaneous (SC) on top of Standard of Care (SoC) every 4 weeks during the 52-week treatment period.	Placebo n=85 Participants Participants received one dose of matching placebo via SC route on top of SoC, every 4 weeks during the 52-week treatment period.
Mean Change From Baseline in Mean Overall VAS Symptom Score During the 4 Weeks Prior to Week 52 - ITT Population	-3.31 Scores on a Scale Standard Error 0.346	-1.77 Scores on a Scale Standard Error 0.350

SECONDARY outcome

Timeframe: Baseline (Day 1) and Week 52

Population: The analysis was performed on the ITT Set (randomized participants who received at least 1 dose of study treatment) excluding participants from Medipharma managed sites. Participants were analyzed according to the treatment they were allocated at randomization.

The LMK CT scoring system is based on localization with points given for degree of opacification: 0 =normal, 1 = partial opacification, 2 = total opacification. These points are then applied to the maxillary, anterior ethmoid, posterior ethmoid, sphenoid, frontal sinus on each side. The osteomeatal complex (OC) was graded as 0 = not occluded, or 2 = occluded deriving a maximum score of 12 per side. The range for the LMK CT score is therefore 0-24 (higher scores indicating more opacification) when summed across both sides. Baseline was defined as Day 1 value. Change from Baseline = Post-baseline value minus Baseline value.

Outcome measures

Outcome measures
Measure	Mepolizumab n=80 Participants Participants received one dose of 100 mg/mL mepolizumab subcutaneous (SC) on top of Standard of Care (SoC) every 4 weeks during the 52-week treatment period.	Placebo n=83 Participants Participants received one dose of matching placebo via SC route on top of SoC, every 4 weeks during the 52-week treatment period.
Mean Change From Baseline in Lund Mackay (LMK) Computed Tomography (CT) Score at Week 52 - ITT Population Excluding Medipharma Managed Sites	-3.52 Scores on a Scale Standard Error 0.449	-1.88 Scores on a Scale Standard Error 0.452

SECONDARY outcome

Timeframe: Baseline (Day 1) and Week 52

Population: The analysis was performed on the ITT Set (randomized participants who received at least 1 dose of study treatment) excluding participants from Medipharma managed sites. Participants were analyzed according to the treatment they were allocated at randomization.

The LMK CT scoring system is based on localization with points given for degree of opacification: 0 =normal, 1 = partial opacification, 2 = total opacification. These points are then applied to the maxillary, anterior ethmoid, posterior ethmoid, sphenoid, frontal sinus on each side of the nostril. The osteomeatal complex (OC) was graded as 0 = not occluded, or 2 = occluded deriving a maximum score of 12 per side. The range for the LMK CT score is therefore 0-24 (higher scores indicating more opacification) when summed across both sides. Baseline was defined as Day 1 value. Change from Baseline = Post-baseline value minus Baseline value.

Outcome measures

Outcome measures
Measure	Mepolizumab n=84 Participants Participants received one dose of 100 mg/mL mepolizumab subcutaneous (SC) on top of Standard of Care (SoC) every 4 weeks during the 52-week treatment period.	Placebo n=85 Participants Participants received one dose of matching placebo via SC route on top of SoC, every 4 weeks during the 52-week treatment period.
Mean Change From Baseline in LMK CT Score at Week 52 - ITT Population	-3.55 Scores on a Scale Standard Error 0.442	-1.88 Scores on a Scale Standard Error 0.454

SECONDARY outcome

Timeframe: Baseline (Day 1) up to 4 weeks prior to week 52

Population: The analysis was performed on the ITT Set (randomized participants who received at least 1 dose of study treatment) excluding participants from Medipharma managed sites. Participants were analyzed according to the treatment they were allocated at randomization. Analysis was performed using MAR assumption to handle missing data.

Participants rated individual (nasal obstruction, nasal discharge, mucus in the throat, loss of smell, facial pain) and overall symptoms on a visual analog scale using an eDiary. Captured scores ranged between 0 (none) and 100 (as bad as you can imagine), final scores derived from electronically captured scores by dividing by 10. The composite VAS score was calculated as average of individual scores of nasal obstruction, nasal discharge, mucus in the throat and loss of smell and ranged between 0 (none) and 10 (worst), with higher scores indicating greater disease severity. The average of daily scores in 4-weekly intervals were calculated and data is presented for Weeks 49-52. Baseline was defined as the average score from the 7 days of eDiary data collected prior to Day 1. Change from Baseline = Post-baseline value minus Baseline value.

Outcome measures

Outcome measures
Measure	Mepolizumab n=80 Participants Participants received one dose of 100 mg/mL mepolizumab subcutaneous (SC) on top of Standard of Care (SoC) every 4 weeks during the 52-week treatment period.	Placebo n=83 Participants Participants received one dose of matching placebo via SC route on top of SoC, every 4 weeks during the 52-week treatment period.
Mean Change From Baseline in the Mean Composite VAS Score [Combining VAS Scores for Nasal Obstruction, Nasal Discharge, Mucus in the Throat and Loss of Smell] During the 4 Weeks Prior to Week 52 - ITT Population Excluding Medipharma Managed Sites	-2.64 Scores on a Scale Standard Error 0.294	-1.47 Scores on a Scale Standard Error 0.291

SECONDARY outcome

Timeframe: Baseline (Day 1) up to 4 weeks prior to week 52

Population: The analysis was performed on the ITT Set that included all randomized participants who received at least 1 dose of study treatment. Participants were analyzed according to the treatment they were allocated at randomization. Analysis was performed using MAR assumption to handle missing data.

Participants rated individual (nasal obstruction, nasal discharge, mucus in the throat, loss of smell, facial pain) and overall symptoms on a visual analog scale using an eDiary. Captured scores ranged between 0 (none) and 100 (as bad as you can imagine), final scores derived from electronically captured scores by dividing by 10. The composite VAS score was calculated as average of individual scores of nasal obstruction, nasal discharge, mucus in the throat and loss of smell and ranged between 0 (none) and 10 (worst), with higher scores indicating greater disease severity. The average of daily scores in 4-weekly intervals were calculated and data is presented for Weeks 49-52. Baseline was defined as the average score from the 7 days of eDiary data collected prior to Day 1. Change from Baseline = Post-baseline value minus Baseline value.

Outcome measures

Outcome measures
Measure	Mepolizumab n=84 Participants Participants received one dose of 100 mg/mL mepolizumab subcutaneous (SC) on top of Standard of Care (SoC) every 4 weeks during the 52-week treatment period.	Placebo n=85 Participants Participants received one dose of matching placebo via SC route on top of SoC, every 4 weeks during the 52-week treatment period.
Mean Change From Baseline in the Mean Composite VAS Score [Combining VAS Scores for Nasal Obstruction, Nasal Discharge, Mucus in the Throat and Loss of Smell] During the 4 Weeks Prior to Week 52 - ITT Population	-2.64 Scores on a Scale Standard Error 0.289	-1.44 Scores on a Scale Standard Error 0.291

SECONDARY outcome

Timeframe: Baseline (Day 1) up to Week 52

Population: The analysis was performed on the ITT Set (randomized participants who received at least 1 dose of study treatment) excluding participants from Medipharma managed sites and 1 participant who did not have baseline SNOT. Participants were analyzed according to the treatment they were allocated at randomization. Analysis was performed using MAR assumption to handle post-baseline missing data.

SNOT-22 is a 22-item measure of disease specific health related quality of life (HRQoL). Participants were asked to rate the severity of their condition on each of the 22 items over the previous 2 weeks using a 6-point rating scale of 0-5 including: 0 =Not present/no problem; 1 =Very mild problem; 2 = Mild or slight problem; 3 = Moderate problem; 4 = Severe problem; 5=Problem as "bad as it can be". The scores for each question were summed up to derive the total score range for the SNOT-22 was from 0 (high quality of life) to 110 (worst quality of life), where higher scores representing worse quality of life. Baseline was defined as Day 1 value. Change from Baseline = Post-baseline value minus Baseline value.

Outcome measures

Outcome measures
Measure	Mepolizumab n=79 Participants Participants received one dose of 100 mg/mL mepolizumab subcutaneous (SC) on top of Standard of Care (SoC) every 4 weeks during the 52-week treatment period.	Placebo n=83 Participants Participants received one dose of matching placebo via SC route on top of SoC, every 4 weeks during the 52-week treatment period.
Mean Change From Baseline in Sino-nasal Outcome Test (SNOT)-22 Total Score at Week 52 - ITT Population Excluding Medipharma Managed Sites	-18.27 Scores on a Scale Standard Error 2.889	-7.65 Scores on a Scale Standard Error 2.869

SECONDARY outcome

Timeframe: Baseline (Day 1) up to Week 52

Population: The analysis was performed on the ITT Set that included all randomized participants who received at least 1 dose of study treatment. Participants were analyzed according to the treatment they were allocated at randomization. Only those participants with data available at specified time points have been analyzed.

SNOT-22 is a 22-questions measure of disease specific health related quality of life (HRQoL). Participants were asked to rate the severity of their condition on each of the 22 items over the previous 2 weeks using a 6-point rating scale of 0-5 including: 0 =Not present/no problem; 1 =Very mild problem; 2 = Mild or slight problem; 3 = Moderate problem; 4 = Severe problem; 5=Problem as "bad as it can be". The scores for each question were summed up to derive the total score range for all SNOT-22 items ranging from 0 (high quality of life) to 110 (worst quality of life). Lower score indicating better HRQoL. Baseline was defined as Day 1 value. Change from Baseline = Post-baseline value minus Baseline value.

Outcome measures

Outcome measures
Measure	Mepolizumab n=83 Participants Participants received one dose of 100 mg/mL mepolizumab subcutaneous (SC) on top of Standard of Care (SoC) every 4 weeks during the 52-week treatment period.	Placebo n=85 Participants Participants received one dose of matching placebo via SC route on top of SoC, every 4 weeks during the 52-week treatment period.
Mean Change From Baseline in Sino-nasal Outcome Test (SNOT)-22 Total Score at Week 52 - ITT Population	-18.98 Scores on a Scale Standard Error 2.771	-7.58 Scores on a Scale Standard Error 2.806

SECONDARY outcome

Timeframe: Baseline (Day 1) up to 4 weeks prior to week 52

Population: The analysis was performed on the ITT Set (randomized participants who received at least 1 dose of study treatment) excluding participants from Medipharma managed sites. Participants were analyzed according to the treatment they were allocated at randomization. Analysis was performed using MAR assumption to handle missing data.

Participants rated individual (nasal obstruction, nasal discharge, mucus in the throat, loss of smell, facial pain) and overall symptoms on a visual analog scale using an eDiary. Captured scores ranged between 0 (none) and 100 (as bad as you can imagine), final scores derived from the electronically captured scores by dividing by 10. The final loss of smell VAS score ranged between 0 (none) and 10 (worst), with higher scores indicating greater disease severity. The average of daily scores in 4-weekly intervals were calculated and data is presented for Weeks 49-52. Baseline was defined as the average score from the 7 days of eDiary data collected prior to Day 1. Change from Baseline = Post-baseline value minus Baseline value.

Outcome measures

Outcome measures
Measure	Mepolizumab n=80 Participants Participants received one dose of 100 mg/mL mepolizumab subcutaneous (SC) on top of Standard of Care (SoC) every 4 weeks during the 52-week treatment period.	Placebo n=83 Participants Participants received one dose of matching placebo via SC route on top of SoC, every 4 weeks during the 52-week treatment period.
Mean Change From Baseline in Mean Individual VAS Symptom Score for Loss of Smell During the 4 Weeks Prior to Week 52 - ITT Population Excluding Medipharma Managed Sites	-1.71 Scores on a Scale Standard Error 0.220	-0.89 Scores on a Scale Standard Error 0.219

SECONDARY outcome

Timeframe: Baseline (Day 1) up to 4 weeks prior to week 52

Population: The analysis was performed on the ITT Set that included all randomized participants who received at least 1 dose of study treatment. Participants were analyzed according to the treatment they were allocated at randomization. Analysis was performed using MAR assumption to handle missing data.

Participants rated individual (nasal obstruction, nasal discharge, mucus in the throat, loss of smell, facial pain) and overall symptoms on a visual analog scale using an eDiary. Captured scores ranged between 0 (none) and 100 (as bad as you can imagine), final scores derived from the electronically captured scores by dividing by 10. The final loss of smell VAS score ranged between 0 (none) and 10 (worst), with higher scores indicating greater disease severity. The average of daily scores in 4-weekly intervals were calculated and data is presented for Weeks 49-52. Baseline was defined as the average score from the 7 days of eDiary data collected prior to Day 1. Change from Baseline = Post-baseline value minus Baseline value.

Outcome measures

Outcome measures
Measure	Mepolizumab n=84 Participants Participants received one dose of 100 mg/mL mepolizumab subcutaneous (SC) on top of Standard of Care (SoC) every 4 weeks during the 52-week treatment period.	Placebo n=85 Participants Participants received one dose of matching placebo via SC route on top of SoC, every 4 weeks during the 52-week treatment period.
Change From Baseline in Mean Individual VAS Symptom Score for Loss of Smell During the 4 Weeks Prior to Week 52 - ITT Population	-1.76 Scores on a Scale Standard Error 0.215	-0.87 Scores on a Scale Standard Error 0.219

SECONDARY outcome

Timeframe: At Week 8, 16, 24, 32, 40, 48 and Week 52

Population: The analysis was performed on the ITT Set (randomized participants who received at least 1 dose of study treatment) excluding participants from Medipharma managed sites. Participants were analyzed according to the treatment they were allocated at randomization.

NP surgery is defined as any procedure involving instruments resulting in incision and removal of tissue from the nasal cavity (for example polypectomy). Additionally, the number of courses of systemic steroids and reason for treatment will be recorded throughout the study. Percentage of participants with nasal surgery or course of systemic CS for CRSwNP/ECRS and corresponding 95% CI have been presented, calculated using the Kaplan-Meier method.

Outcome measures

Outcome measures
Measure	Mepolizumab n=80 Participants Participants received one dose of 100 mg/mL mepolizumab subcutaneous (SC) on top of Standard of Care (SoC) every 4 weeks during the 52-week treatment period.	Placebo n=83 Participants Participants received one dose of matching placebo via SC route on top of SoC, every 4 weeks during the 52-week treatment period.
Percentage of Participants With Nasal Surgery or Systemic Corticosteroids (CS) for Chronic Rhinosinusitis With Nasal Polyposis/Eosinophilic Chronic Rhinosinusitis (CRSwNP/ECRS) Over Time- ITT Population Excluding Medipharma Managed Sites Week 8	3.7 Percentage of participants Interval 1.2 to 11.2	4.9 Percentage of participants Interval 1.9 to 12.5
Percentage of Participants With Nasal Surgery or Systemic Corticosteroids (CS) for Chronic Rhinosinusitis With Nasal Polyposis/Eosinophilic Chronic Rhinosinusitis (CRSwNP/ECRS) Over Time- ITT Population Excluding Medipharma Managed Sites Week 16	10.1 Percentage of participants Interval 5.2 to 19.1	13.5 Percentage of participants Interval 7.7 to 23.1
Percentage of Participants With Nasal Surgery or Systemic Corticosteroids (CS) for Chronic Rhinosinusitis With Nasal Polyposis/Eosinophilic Chronic Rhinosinusitis (CRSwNP/ECRS) Over Time- ITT Population Excluding Medipharma Managed Sites Week 24	13.9 Percentage of participants Interval 7.9 to 23.6	22.4 Percentage of participants Interval 14.7 to 33.1
Percentage of Participants With Nasal Surgery or Systemic Corticosteroids (CS) for Chronic Rhinosinusitis With Nasal Polyposis/Eosinophilic Chronic Rhinosinusitis (CRSwNP/ECRS) Over Time- ITT Population Excluding Medipharma Managed Sites Week 32	16.4 Percentage of participants Interval 9.9 to 26.6	23.7 Percentage of participants Interval 15.8 to 34.6
Percentage of Participants With Nasal Surgery or Systemic Corticosteroids (CS) for Chronic Rhinosinusitis With Nasal Polyposis/Eosinophilic Chronic Rhinosinusitis (CRSwNP/ECRS) Over Time- ITT Population Excluding Medipharma Managed Sites Week 40	19.0 Percentage of participants Interval 11.9 to 29.6	30.4 Percentage of participants Interval 21.5 to 41.8
Percentage of Participants With Nasal Surgery or Systemic Corticosteroids (CS) for Chronic Rhinosinusitis With Nasal Polyposis/Eosinophilic Chronic Rhinosinusitis (CRSwNP/ECRS) Over Time- ITT Population Excluding Medipharma Managed Sites Week 48	20.4 Percentage of participants Interval 13.0 to 31.2	35.8 Percentage of participants Interval 26.3 to 47.6
Percentage of Participants With Nasal Surgery or Systemic Corticosteroids (CS) for Chronic Rhinosinusitis With Nasal Polyposis/Eosinophilic Chronic Rhinosinusitis (CRSwNP/ECRS) Over Time- ITT Population Excluding Medipharma Managed Sites Week 52	20.4 Percentage of participants Interval 13.0 to 31.2	35.8 Percentage of participants Interval 26.3 to 47.6

SECONDARY outcome

Timeframe: At Week 8, 16, 24, 32, 40, 48 and Week 52

Population: The analysis was performed on the ITT Set that included all randomized participants who received at least 1 dose of study treatment. Participants were analyzed according to the treatment they were allocated at randomization. Analysis was performed using MAR assumption to handle missing data.

NP surgery is defined as any procedure involving instruments resulting in incision and removal of tissue from the nasal cavity (for example polypectomy). Additionally, the number of courses of systemic steroids and reason for treatment will be recorded throughout the study. Percentage of participants with nasal surgery or course of systemic CS for CRSwNP/ECRS and corresponding 95% CI have been presented, calculated using the Kaplan-Meier method.

Outcome measures

Outcome measures
Measure	Mepolizumab n=84 Participants Participants received one dose of 100 mg/mL mepolizumab subcutaneous (SC) on top of Standard of Care (SoC) every 4 weeks during the 52-week treatment period.	Placebo n=85 Participants Participants received one dose of matching placebo via SC route on top of SoC, every 4 weeks during the 52-week treatment period.
Percentage of Participants With Nasal Surgery or Course of Systemic CS for CRSwNP/ECRS up to Week 52 - ITT Population Week 48	27.2 Percentage of participants Interval 16.5 to 43.0	46.6 Percentage of participants Interval 33.0 to 62.5
Percentage of Participants With Nasal Surgery or Course of Systemic CS for CRSwNP/ECRS up to Week 52 - ITT Population Week 52	27.2 Percentage of participants Interval 16.5 to 43.0	46.6 Percentage of participants Interval 33.0 to 62.5
Percentage of Participants With Nasal Surgery or Course of Systemic CS for CRSwNP/ECRS up to Week 52 - ITT Population Week 8	4.4 Percentage of participants Interval 1.1 to 16.6	8.9 Percentage of participants Interval 3.4 to 22.0
Percentage of Participants With Nasal Surgery or Course of Systemic CS for CRSwNP/ECRS up to Week 52 - ITT Population Week 16	13.5 Percentage of participants Interval 6.3 to 27.6	20.5 Percentage of participants Interval 11.2 to 35.8
Percentage of Participants With Nasal Surgery or Course of Systemic CS for CRSwNP/ECRS up to Week 52 - ITT Population Week 24	20.3 Percentage of participants Interval 11.1 to 35.4	29.9 Percentage of participants Interval 18.6 to 45.9
Percentage of Participants With Nasal Surgery or Course of Systemic CS for CRSwNP/ECRS up to Week 52 - ITT Population Week 32	24.9 Percentage of participants Interval 14.6 to 40.4	32.2 Percentage of participants Interval 20.5 to 48.3
Percentage of Participants With Nasal Surgery or Course of Systemic CS for CRSwNP/ECRS up to Week 52 - ITT Population Week 40	24.9 Percentage of participants Interval 14.6 to 40.4	41.7 Percentage of participants Interval 28.7 to 57.8

Adverse Events

Mepolizumab

Serious events: 0 serious events

Other events: 47 other events

Deaths: 0 deaths

Placebo

Serious events: 3 serious events

Other events: 52 other events

Deaths: 0 deaths

Serious adverse events

Serious adverse events
Measure	Mepolizumab n=84 participants at risk Participants received one dose of 100 mg/mL mepolizumab subcutaneous (SC) on top of Standard of Care (SoC) every 4 weeks during the 52-week treatment period.	Placebo n=85 participants at risk Participants received one dose of matching placebo via SC route on top of SoC, every 4 weeks during the 52-week treatment period.
Neoplasms benign, malignant and unspecified (incl cysts and polyps) Breast cancer	0.00% 0/84 • From Day 1 (first dose) to Week 52 The safety population included all randomized participants who received at least 1 dose of study treatment. On-treatment Adverse event (AEs) and serious adverse event (SAEs) occurred from first dose of mepolizumab to last dose of mepolizumab + 28 days inclusive.	1.2% 1/85 • Number of events 1 • From Day 1 (first dose) to Week 52 The safety population included all randomized participants who received at least 1 dose of study treatment. On-treatment Adverse event (AEs) and serious adverse event (SAEs) occurred from first dose of mepolizumab to last dose of mepolizumab + 28 days inclusive.
Respiratory, thoracic and mediastinal disorders Asthma	0.00% 0/84 • From Day 1 (first dose) to Week 52 The safety population included all randomized participants who received at least 1 dose of study treatment. On-treatment Adverse event (AEs) and serious adverse event (SAEs) occurred from first dose of mepolizumab to last dose of mepolizumab + 28 days inclusive.	1.2% 1/85 • Number of events 1 • From Day 1 (first dose) to Week 52 The safety population included all randomized participants who received at least 1 dose of study treatment. On-treatment Adverse event (AEs) and serious adverse event (SAEs) occurred from first dose of mepolizumab to last dose of mepolizumab + 28 days inclusive.
Respiratory, thoracic and mediastinal disorders Chronic rhinosinusitis with nasal polyps	0.00% 0/84 • From Day 1 (first dose) to Week 52 The safety population included all randomized participants who received at least 1 dose of study treatment. On-treatment Adverse event (AEs) and serious adverse event (SAEs) occurred from first dose of mepolizumab to last dose of mepolizumab + 28 days inclusive.	1.2% 1/85 • Number of events 1 • From Day 1 (first dose) to Week 52 The safety population included all randomized participants who received at least 1 dose of study treatment. On-treatment Adverse event (AEs) and serious adverse event (SAEs) occurred from first dose of mepolizumab to last dose of mepolizumab + 28 days inclusive.
Skin and subcutaneous tissue disorders Pemphigoid	0.00% 0/84 • From Day 1 (first dose) to Week 52 The safety population included all randomized participants who received at least 1 dose of study treatment. On-treatment Adverse event (AEs) and serious adverse event (SAEs) occurred from first dose of mepolizumab to last dose of mepolizumab + 28 days inclusive.	1.2% 1/85 • Number of events 1 • From Day 1 (first dose) to Week 52 The safety population included all randomized participants who received at least 1 dose of study treatment. On-treatment Adverse event (AEs) and serious adverse event (SAEs) occurred from first dose of mepolizumab to last dose of mepolizumab + 28 days inclusive.
Infections and infestations Pneumonia	0.00% 0/84 • From Day 1 (first dose) to Week 52 The safety population included all randomized participants who received at least 1 dose of study treatment. On-treatment Adverse event (AEs) and serious adverse event (SAEs) occurred from first dose of mepolizumab to last dose of mepolizumab + 28 days inclusive.	1.2% 1/85 • Number of events 1 • From Day 1 (first dose) to Week 52 The safety population included all randomized participants who received at least 1 dose of study treatment. On-treatment Adverse event (AEs) and serious adverse event (SAEs) occurred from first dose of mepolizumab to last dose of mepolizumab + 28 days inclusive.

Other adverse events

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	Mepolizumab n=84 participants at risk Participants received one dose of 100 mg/mL mepolizumab subcutaneous (SC) on top of Standard of Care (SoC) every 4 weeks during the 52-week treatment period.	Placebo n=85 participants at risk Participants received one dose of matching placebo via SC route on top of SoC, every 4 weeks during the 52-week treatment period.
Gastrointestinal disorders Diarrhoea	4.8% 4/84 • Number of events 4 • From Day 1 (first dose) to Week 52 The safety population included all randomized participants who received at least 1 dose of study treatment. On-treatment Adverse event (AEs) and serious adverse event (SAEs) occurred from first dose of mepolizumab to last dose of mepolizumab + 28 days inclusive.	1.2% 1/85 • Number of events 1 • From Day 1 (first dose) to Week 52 The safety population included all randomized participants who received at least 1 dose of study treatment. On-treatment Adverse event (AEs) and serious adverse event (SAEs) occurred from first dose of mepolizumab to last dose of mepolizumab + 28 days inclusive.
Gastrointestinal disorders Stomatitis	0.00% 0/84 • From Day 1 (first dose) to Week 52 The safety population included all randomized participants who received at least 1 dose of study treatment. On-treatment Adverse event (AEs) and serious adverse event (SAEs) occurred from first dose of mepolizumab to last dose of mepolizumab + 28 days inclusive.	3.5% 3/85 • Number of events 3 • From Day 1 (first dose) to Week 52 The safety population included all randomized participants who received at least 1 dose of study treatment. On-treatment Adverse event (AEs) and serious adverse event (SAEs) occurred from first dose of mepolizumab to last dose of mepolizumab + 28 days inclusive.
General disorders Pyrexia	3.6% 3/84 • Number of events 3 • From Day 1 (first dose) to Week 52 The safety population included all randomized participants who received at least 1 dose of study treatment. On-treatment Adverse event (AEs) and serious adverse event (SAEs) occurred from first dose of mepolizumab to last dose of mepolizumab + 28 days inclusive.	4.7% 4/85 • Number of events 5 • From Day 1 (first dose) to Week 52 The safety population included all randomized participants who received at least 1 dose of study treatment. On-treatment Adverse event (AEs) and serious adverse event (SAEs) occurred from first dose of mepolizumab to last dose of mepolizumab + 28 days inclusive.
General disorders Vaccination site pain	3.6% 3/84 • Number of events 5 • From Day 1 (first dose) to Week 52 The safety population included all randomized participants who received at least 1 dose of study treatment. On-treatment Adverse event (AEs) and serious adverse event (SAEs) occurred from first dose of mepolizumab to last dose of mepolizumab + 28 days inclusive.	2.4% 2/85 • Number of events 4 • From Day 1 (first dose) to Week 52 The safety population included all randomized participants who received at least 1 dose of study treatment. On-treatment Adverse event (AEs) and serious adverse event (SAEs) occurred from first dose of mepolizumab to last dose of mepolizumab + 28 days inclusive.
Infections and infestations Acute sinusitis	0.00% 0/84 • From Day 1 (first dose) to Week 52 The safety population included all randomized participants who received at least 1 dose of study treatment. On-treatment Adverse event (AEs) and serious adverse event (SAEs) occurred from first dose of mepolizumab to last dose of mepolizumab + 28 days inclusive.	3.5% 3/85 • Number of events 4 • From Day 1 (first dose) to Week 52 The safety population included all randomized participants who received at least 1 dose of study treatment. On-treatment Adverse event (AEs) and serious adverse event (SAEs) occurred from first dose of mepolizumab to last dose of mepolizumab + 28 days inclusive.
Infections and infestations COVID-19	17.9% 15/84 • Number of events 15 • From Day 1 (first dose) to Week 52 The safety population included all randomized participants who received at least 1 dose of study treatment. On-treatment Adverse event (AEs) and serious adverse event (SAEs) occurred from first dose of mepolizumab to last dose of mepolizumab + 28 days inclusive.	17.6% 15/85 • Number of events 15 • From Day 1 (first dose) to Week 52 The safety population included all randomized participants who received at least 1 dose of study treatment. On-treatment Adverse event (AEs) and serious adverse event (SAEs) occurred from first dose of mepolizumab to last dose of mepolizumab + 28 days inclusive.
Infections and infestations Nasopharyngitis	8.3% 7/84 • Number of events 7 • From Day 1 (first dose) to Week 52 The safety population included all randomized participants who received at least 1 dose of study treatment. On-treatment Adverse event (AEs) and serious adverse event (SAEs) occurred from first dose of mepolizumab to last dose of mepolizumab + 28 days inclusive.	10.6% 9/85 • Number of events 10 • From Day 1 (first dose) to Week 52 The safety population included all randomized participants who received at least 1 dose of study treatment. On-treatment Adverse event (AEs) and serious adverse event (SAEs) occurred from first dose of mepolizumab to last dose of mepolizumab + 28 days inclusive.
Injury, poisoning and procedural complications Immunisation reaction	6.0% 5/84 • Number of events 7 • From Day 1 (first dose) to Week 52 The safety population included all randomized participants who received at least 1 dose of study treatment. On-treatment Adverse event (AEs) and serious adverse event (SAEs) occurred from first dose of mepolizumab to last dose of mepolizumab + 28 days inclusive.	3.5% 3/85 • Number of events 4 • From Day 1 (first dose) to Week 52 The safety population included all randomized participants who received at least 1 dose of study treatment. On-treatment Adverse event (AEs) and serious adverse event (SAEs) occurred from first dose of mepolizumab to last dose of mepolizumab + 28 days inclusive.
Injury, poisoning and procedural complications Post vaccination fever	2.4% 2/84 • Number of events 3 • From Day 1 (first dose) to Week 52 The safety population included all randomized participants who received at least 1 dose of study treatment. On-treatment Adverse event (AEs) and serious adverse event (SAEs) occurred from first dose of mepolizumab to last dose of mepolizumab + 28 days inclusive.	4.7% 4/85 • Number of events 5 • From Day 1 (first dose) to Week 52 The safety population included all randomized participants who received at least 1 dose of study treatment. On-treatment Adverse event (AEs) and serious adverse event (SAEs) occurred from first dose of mepolizumab to last dose of mepolizumab + 28 days inclusive.
Investigations Alanine aminotransferase increased	3.6% 3/84 • Number of events 3 • From Day 1 (first dose) to Week 52 The safety population included all randomized participants who received at least 1 dose of study treatment. On-treatment Adverse event (AEs) and serious adverse event (SAEs) occurred from first dose of mepolizumab to last dose of mepolizumab + 28 days inclusive.	0.00% 0/85 • From Day 1 (first dose) to Week 52 The safety population included all randomized participants who received at least 1 dose of study treatment. On-treatment Adverse event (AEs) and serious adverse event (SAEs) occurred from first dose of mepolizumab to last dose of mepolizumab + 28 days inclusive.
Musculoskeletal and connective tissue disorders Arthralgia	3.6% 3/84 • Number of events 3 • From Day 1 (first dose) to Week 52 The safety population included all randomized participants who received at least 1 dose of study treatment. On-treatment Adverse event (AEs) and serious adverse event (SAEs) occurred from first dose of mepolizumab to last dose of mepolizumab + 28 days inclusive.	2.4% 2/85 • Number of events 2 • From Day 1 (first dose) to Week 52 The safety population included all randomized participants who received at least 1 dose of study treatment. On-treatment Adverse event (AEs) and serious adverse event (SAEs) occurred from first dose of mepolizumab to last dose of mepolizumab + 28 days inclusive.
Musculoskeletal and connective tissue disorders Back pain	3.6% 3/84 • Number of events 3 • From Day 1 (first dose) to Week 52 The safety population included all randomized participants who received at least 1 dose of study treatment. On-treatment Adverse event (AEs) and serious adverse event (SAEs) occurred from first dose of mepolizumab to last dose of mepolizumab + 28 days inclusive.	5.9% 5/85 • Number of events 5 • From Day 1 (first dose) to Week 52 The safety population included all randomized participants who received at least 1 dose of study treatment. On-treatment Adverse event (AEs) and serious adverse event (SAEs) occurred from first dose of mepolizumab to last dose of mepolizumab + 28 days inclusive.
Nervous system disorders Dizziness	2.4% 2/84 • Number of events 2 • From Day 1 (first dose) to Week 52 The safety population included all randomized participants who received at least 1 dose of study treatment. On-treatment Adverse event (AEs) and serious adverse event (SAEs) occurred from first dose of mepolizumab to last dose of mepolizumab + 28 days inclusive.	5.9% 5/85 • Number of events 5 • From Day 1 (first dose) to Week 52 The safety population included all randomized participants who received at least 1 dose of study treatment. On-treatment Adverse event (AEs) and serious adverse event (SAEs) occurred from first dose of mepolizumab to last dose of mepolizumab + 28 days inclusive.
Nervous system disorders Headache	7.1% 6/84 • Number of events 8 • From Day 1 (first dose) to Week 52 The safety population included all randomized participants who received at least 1 dose of study treatment. On-treatment Adverse event (AEs) and serious adverse event (SAEs) occurred from first dose of mepolizumab to last dose of mepolizumab + 28 days inclusive.	7.1% 6/85 • Number of events 11 • From Day 1 (first dose) to Week 52 The safety population included all randomized participants who received at least 1 dose of study treatment. On-treatment Adverse event (AEs) and serious adverse event (SAEs) occurred from first dose of mepolizumab to last dose of mepolizumab + 28 days inclusive.
Respiratory, thoracic and mediastinal disorders Asthma	1.2% 1/84 • Number of events 1 • From Day 1 (first dose) to Week 52 The safety population included all randomized participants who received at least 1 dose of study treatment. On-treatment Adverse event (AEs) and serious adverse event (SAEs) occurred from first dose of mepolizumab to last dose of mepolizumab + 28 days inclusive.	4.7% 4/85 • Number of events 4 • From Day 1 (first dose) to Week 52 The safety population included all randomized participants who received at least 1 dose of study treatment. On-treatment Adverse event (AEs) and serious adverse event (SAEs) occurred from first dose of mepolizumab to last dose of mepolizumab + 28 days inclusive.
Respiratory, thoracic and mediastinal disorders Cough	3.6% 3/84 • Number of events 3 • From Day 1 (first dose) to Week 52 The safety population included all randomized participants who received at least 1 dose of study treatment. On-treatment Adverse event (AEs) and serious adverse event (SAEs) occurred from first dose of mepolizumab to last dose of mepolizumab + 28 days inclusive.	1.2% 1/85 • Number of events 1 • From Day 1 (first dose) to Week 52 The safety population included all randomized participants who received at least 1 dose of study treatment. On-treatment Adverse event (AEs) and serious adverse event (SAEs) occurred from first dose of mepolizumab to last dose of mepolizumab + 28 days inclusive.
Respiratory, thoracic and mediastinal disorders Respiratory disorder	3.6% 3/84 • Number of events 3 • From Day 1 (first dose) to Week 52 The safety population included all randomized participants who received at least 1 dose of study treatment. On-treatment Adverse event (AEs) and serious adverse event (SAEs) occurred from first dose of mepolizumab to last dose of mepolizumab + 28 days inclusive.	1.2% 1/85 • Number of events 1 • From Day 1 (first dose) to Week 52 The safety population included all randomized participants who received at least 1 dose of study treatment. On-treatment Adverse event (AEs) and serious adverse event (SAEs) occurred from first dose of mepolizumab to last dose of mepolizumab + 28 days inclusive.
Skin and subcutaneous tissue disorders Eczema	2.4% 2/84 • Number of events 2 • From Day 1 (first dose) to Week 52 The safety population included all randomized participants who received at least 1 dose of study treatment. On-treatment Adverse event (AEs) and serious adverse event (SAEs) occurred from first dose of mepolizumab to last dose of mepolizumab + 28 days inclusive.	3.5% 3/85 • Number of events 3 • From Day 1 (first dose) to Week 52 The safety population included all randomized participants who received at least 1 dose of study treatment. On-treatment Adverse event (AEs) and serious adverse event (SAEs) occurred from first dose of mepolizumab to last dose of mepolizumab + 28 days inclusive.
Vascular disorders Hypertension	2.4% 2/84 • Number of events 2 • From Day 1 (first dose) to Week 52 The safety population included all randomized participants who received at least 1 dose of study treatment. On-treatment Adverse event (AEs) and serious adverse event (SAEs) occurred from first dose of mepolizumab to last dose of mepolizumab + 28 days inclusive.	4.7% 4/85 • Number of events 4 • From Day 1 (first dose) to Week 52 The safety population included all randomized participants who received at least 1 dose of study treatment. On-treatment Adverse event (AEs) and serious adverse event (SAEs) occurred from first dose of mepolizumab to last dose of mepolizumab + 28 days inclusive.