Efficacy and Safety Study of Mepolizumab Adjunctive Therapy in Subjects With Severe Uncontrolled Refractory Asthma

Phase 3

Completed

Conditions: Asthma

Interventions: Drug: Mepolizumab IV
Drug: Mepolizumab SC
Drug: SC Placebo
Drug: IV Placebo

Registration Number: NCT01691521

Lead Sponsor: GlaxoSmithKline

Brief Summary: This study will evaluate two dose regimens of mepolizumab \[75mg intravenous (i.v.) or 100mg subcutaneous (SC) every 4 weeks\] compared with placebo over a 32 week treatment period in subjects with severe refractory asthma with elevated blood eosinophils. Efficacy will be measured by a reduction in the frequency of asthma exacerbations. Additional efficacy assessments will include measurements of lung function, symptom scores, and quality of life. Safety will be assessed by clinical laboratory samples, ECGs, immunogenicity and adverse events.

This study is intended to replicate the Phase IIb/III study MEA112997. Subjects in MEA115588, who meet all eligibility criteria at screening visit, will enter the run-in period. Those subjects that are not able/eligible to be randomised at the end of the 6 week run-in period will be deemed run-in failures. Subjects will remain on their current maintenance therapy throughout the run-in, double-blind treatment administration and follow-up periods. Subjects who meet the randomisation eligibility criteria will be randomised in a 1:1:1 ratio to receive one of the following treatments every 4 weeks for a total of 8 doses: Mepolizumab 75 miligram (mg) i.v. and placebo SC, or Mepolizumab 100 mg SC and placebo i.v. or Placebo i.v. and placebo SC.

Subjects that receive all 8 doses of double-blind treatment, and meet the eligibility criteria for the Open-Label Extension (OLE) Study, will be offered the opportunity to participate in the OLE trial.

Detailed Description: Not available

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 580

Inclusion Criteria

Able to give written informed consent prior to participation in the study
At least 12 years of age at visit 1 and a minimum weight of 45 kilogram (kg)
A well-documented requirement for regular treatment with high dose inhaled corticosteroid (ICS) in the 12 months prior to Visit 1 with or without maintenance oral corticosteroids (OCS)
Current treatment with an additional controller medication, besides ICS, for at least 3 months or a documented failure in the past 12 months of an additional controller medication for at least 3 successive months
Prior documentation of eosinophilic asthma or high likelihood of eosinophilic asthma
At Visit 1, a pre-bronchodilator FEV1 <80% (for subjects >= 18 years of age), a pre-bronchodilator FEV1 <90% or FEV1:FVC ratio <0.8 (for subjects 12-17 years of age).
Previously confirmed history of two or more exacerbations requiring treatment with systemic CS
Male or Eligible Female (females of childbearing potential must commit to consistent and correct use of an acceptable method of birth control)
French subjects will be included only if either affiliated to or a beneficiary of a social security category.

Exclusion Criteria

Current smokers or former smokers with a smoking history of >=10 pack years
Presence of a known pre-existing, clinically important lung condition other than asthma
A current malignancy or previous history of malignancy in less than 12 months
Known, pre-existing, unstable liver disease cirrhosis and known biliary abnormalities
Known, pre-existing severe or clinically significant cardiovascular disease
known, pre-existing other concurrent clinically significant medical conditions that are uncontrolled with standard treatment
Subjects with any eosinophilic diseases
QTc(F) ≥450msec or QTc(F) ≥480 msec
A history of alcohol/substance abuse
Subject with known immunodeficiency
Subjects who have received omalizumab within 130 days of Visit 1 or any monoclonal antibody (other than Xolair) to treat inflammatory disease within 5 half-lives of Visit 1
Subjects who have received treatment with an investigational drug within the past 30 days or five terminal phase half-lives of the drug whichever is longer
Subjects with allergy/intolerance to a monoclonal antibody or biologic.
Subjects who are pregnant or breastfeeding
Subjects who have known evidence of lack of adherence to controller medications and/or ability to follow physician's recommendations
Previously participated in any study with mepolizumab and received investigational product (including placebo)

Study & Design

Study Type: INTERVENTIONAL

Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Mepolizumab IV	Mepolizumab IV	Mepolizumab 75 mg will be administered intravenously approximately every 4 weeks with the last dose at week 32. Subjects in the Mepolizumab IV arm will receive mepolizumab 75 mg intravenously and placebo SC once every 4 weeks with the last dose at Week 28 (total of 8 doses)
Mepolizumab IV	SC Placebo	Mepolizumab 75 mg will be administered intravenously approximately every 4 weeks with the last dose at week 32. Subjects in the Mepolizumab IV arm will receive mepolizumab 75 mg intravenously and placebo SC once every 4 weeks with the last dose at Week 28 (total of 8 doses)
Mepolizumab SC	IV Placebo	Subjects in the Mepolizumab SC arm will receive mepolizumab 100 mg SC and placebo IV once every 4 weeks with the last dose at Week 28 (total of 8 doses)
Placebo	SC Placebo	Subjects in the Placebo arm will receive matching placebo SC and placebo IV once every 4 weeks with the last dose at Week 28 (total of 8 doses)
Mepolizumab SC	Mepolizumab SC	Subjects in the Mepolizumab SC arm will receive mepolizumab 100 mg SC and placebo IV once every 4 weeks with the last dose at Week 28 (total of 8 doses)
Placebo	IV Placebo	Subjects in the Placebo arm will receive matching placebo SC and placebo IV once every 4 weeks with the last dose at Week 28 (total of 8 doses)

Primary Outcome Measures

Name	Time	Method
Number of Clinically Significant Exacerbations of Asthma Per Year	From randomization (Week 0) to Week 32 or if Early Withdrawal (EW) 4 weeks post last dose	Clinically significant exacerbations of asthma are defined as worsening of asthma which required use of systemic corticosteroids (IV or oral steroid like prednisone, for at least 3 days or a single intramuscular (IM) corticosteroid (CS) dose is required. For maintenance of systemic corticosteroids, at least double the existing maintenance dose for at least 3 days was required) and/or hospitalization and/or emergency department (ED) visits. The frequency of clinically significant exacerbations of asthma over the 32-week treatment period is expressed as the number of exacerbations per year. Analysis of the number of exacerbations performed using a negative binomial model with covariates of treatment group, baseline maintenance OCS therapy (OCS vs. no OCS), region, exacerbations in the year prior to the study (as an ordinal variable) and baseline % predicted FEV1, and with logarithm of time on treatment as an offset variable.

Secondary Outcome Measures

Name	Time	Method
Number of Clinically Significant Exacerbations Requiring Hospitalization (Including Intubation and Admittance to an Intensive Care Unit [ICU]) or ED Visits Per Year	From randomization (Week 0) to Week 32 or if Early Withdrawal (EW) 4 weeks post last dose	Clinically significant exacerbations of asthma are defined as worsening of asthma which required use of systemic corticosteroids (IV or oral steroid like prednisone, for at least 3 days or a single intramuscular (IM) corticosteroid (CS) dose is required. For maintenance of systemic corticosteroids, at least double the existing maintenance dose for at least 3 days was required) and/or hospitalization and/or emergency department (ED) visits. The frequency of clinically significant exacerbations of asthma over the 32-week treatment period is expressed as the number of exacerbations per year. Analysis of the number of exacerbations performed using a negative binomial model with covariates of treatment group, baseline maintenance OCS therapy (OCS vs. no OCS), region, exacerbations in the year prior to the study (as an ordinal variable) and baseline % predicted FEV1, and with logarithm of time on treatment as an offset variable.
Number of Clinically Significant Exacerbations Requiring Hospitalization (Including Intubation and Admittance to an ICU) Per Year	From randomization (Week 0) to Week 32 or if Early Withdrawal (EW) 4 weeks post last dose	Clinically significant exacerbations of asthma is defined as worsening of asthma which required use of systemic corticosteroids (IV or oral steroid like prednisone, for at least 3 days or a single intramuscular (IM) corticosteroid (CS) dose is required. For maintenance of systemic corticosteroids, at least double the existing maintenance dose for at least 3 days was required) and/or hospitalization. The frequency of clinically significant exacerbations of asthma over the 32-week treatment period is expressed as the number of exacerbations per year. Analysis of the number of exacerbations performed using a negative binomial model with covariates of treatment group, baseline maintenance OCS therapy (OCS vs. no OCS), region, exacerbations in the year prior to the study (as an ordinal variable) and baseline % predicted FEV1, and with logarithm of time on treatment as an offset variable.
Mean Change From Baseline in Clinic Pre-bronchodilator Forced Expiratory Volume in 1 Second (FEV1) at Week 32	Baseline, Week 32	FEV1 is defined as the volume of air expelled from the lungs in 1 second. Pre-bronchodilator FEV1 measurements were taken by spirometry. The change from Baseline is defined as the difference between the value of the endpoint at the time point of interest and the baseline value. Analysis performed using mixed model repeated measures with covariates of baseline, region, baseline maintenance OCS therapy (OCS vs. no OCS), exacerbations in the year prior to the study (as an ordinal variable), treatment and visit, plus interaction terms for visit by baseline and visit by treatment group.
Mean Change From Baseline in the St. George's Respiratory Questionnaire Total Score at Week 32	Baseline, Week 32	The St. George's Respiratory Questionnaire is an established instrument, comprising 50 questions, evaluating symptoms, activity, and impacts; to measure Quality of Life in participants with diseases of airway obstruction and to elicit the participant's opinion of his/her health. The lowest possible value is zero and the highest possible value is 100. The higher values correspond to greater impairment in quality of life. The questionnaire was administered at Baseline (Visit 2) and at the Exit Visit (approximately 4 weeks after the last dose of study treatment). The change from baseline is defined as the difference between the value of the endpoint at the time point of interest and the baseline value. Analysis performed using analysis of covariance with covariates of baseline, region, baseline maintenance OCS therapy (OCS vs. no OCS), exacerbations in the year prior to the study (as an ordinal variable), baseline % predicted FEV1, and treatment.