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A Multi-center, Open-label Extension, Safety Study of Mepolizumab in Subjects With Hypereosinophilic Syndrome (HES) From Study 200622

A Multi-centre, Open-label Extension, Safety Study to Describe the Long-term Clinical Experience of Mepolizumab in Participants With Hypereosinophilic Syndrome (HES) From Study 200622

Status
Completed
Phases
Phase 3
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT03306043
Enrollment
102
Registered
2017-10-10
Start date
2017-11-13
Completion date
2019-12-30
Last updated
2020-06-23

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

Conditions

Hypereosinophilic Syndrome

Keywords

hypereosinophilic syndrome, hypereosinophilic syndrome flare, open-label extension study, Mepolizumab, SB240563, Long-term safety

Brief summary

This is an open-label extension study to Study 200622.In this study subjects from Study 200622 will be continued on 4-weekly dosing with open-label mepolizumab 300 milligram (mg) subcutaneously (SC) for an additional 20 Weeks after completing the 32 Week study assessments post-randomization, while they continue with their background HES therapy per standard of care (SoC). Subjects from study 200622 will participate in this extension study if they had completed the 32-Week treatment period in study 200622 or if they were withdrawn from the study pre-maturely, but were continued in the study per protocol until 32 Weeks from randomization. Data from this study (205203) and 200622 will be combined to provide up to 52-Week exposure data to further characterize the long-term safety profile of mepolizumab and provide additional data on the clinical benefit in HES subjects beyond 32 Weeks. The duration of the study participation will be 20 Weeks for subjects who continue with mepolizumab treatment via MHE104317/MHE112562 after this open-label extension study; and 28 Weeks for subjects who do not continue with MHE104317/MHE112562.

Interventions

DRUGMepolizumab

Mepolizumab will be available as 100 mg vial for injection. Subjects will receive three 100 mg SC injections for every 4 Weeks for a total of 5 doses during 20 Week treatment period.

Sponsors

GlaxoSmithKline
Lead SponsorINDUSTRY

Study design

Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT
Masking
NONE

Intervention model description

A single group of subjects will receive 300 mg SC mepolizumab every 4 Weeks.

Eligibility

Sex/Gender
ALL
Age
12 Years to No maximum
Healthy volunteers
No

Inclusion criteria

* Age 12 years and older subjects who were enrolled in Study 200622. * To be considered for Study 205203, subjects from study 200622 must have completed 32-Week treatment period in the study or if the subject was withdrawn from study treatment prematurely during the 200622 study, but continued in the study per protocol (including HES flare-related assessments) until 32 Weeks from randomization. * Male or female subjects. Female subjects must be either not a woman of childbearing potential (WOCBP) or WOCBP who agrees to follow the contraceptive guidance at least 30 days prior to the first dose of study treatment and until 16 weeks after the last dose of study treatment. * The treating physician must confirm a positive benefit/risk ratio. The anticipated clinical benefit from mepolizumab must outweigh any potential safety or tolerability risk in Study 205203. * Capable of giving signed informed consent.

Exclusion criteria

* Subjects with any history of hypersensitivity to any monoclonal antibody (including mepolizumab). * Subjects with current malignancy or malignancy that developed during Study 200622. * Subjects who is pregnant or breastfeeding. * Subjects who has other clinically significant medical conditions uncontrolled with SoC therapy not associated with HES, example (e. g.), unstable liver disease, uncontrolled cardiovascular disease, ongoing active infectious disease. * Subjects with QT interval corrected (QTc) greater than 450 millisecond (msec) or QTc greater than 480 msec in subjects with bundle branch block based on local Electrocardiogram (EGC) reading. * Subjects who discontinue study treatment based on liver chemistry stopping criteria during Study 200622. * Current active liver or biliary disease (with the exception of Gilbert's syndrome or asymptomatic gallstones or otherwise stable chronic liver disease per investigator assessment). * Subjects who have received treatment with an investigational agent (biologic or non-biologic) within the past 30 days or 5 drug half-lives whichever is longer, prior to the first dose, other than Study 200622 study treatment. The term investigational applies to any drug not approved for sale for the disease/indication to treat in the country in which it is being used or investigational formulations of marketed products. * Subjects who are currently participating in any other interventional clinical study. * Subjects had an AE (serious or non-serious) considered related to study treatment while participating in Study 200622 which resulted in permanent withdrawal of study treatment.

Design outcomes

Primary

MeasureTime frameDescription
Number of Participants With Common (>=3%) Non-serious Adverse Events (AEs)Up to Week 20An AE was any untoward medical occurrence in a clinical study participant, temporally associated with the use of a study treatment, whether or not considered related to the study treatment. Serious AE was 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 persistent disability/incapacity, congenital anomaly/birth defect or any other situation according to medical or scientific judgment. Non-serious AEs from start of study treatment until 28 days after last dose (up to Week 20) are reported. Number of participants with common (\>=3% incidence) non-serious AEs are presented.
Number of Participants With Serious AEsUp to Week 28An AE was any untoward medical occurrence in a clinical study participant, temporally associated with the use of a study treatment, whether or not considered related to the study treatment. Serious AE was 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 persistent disability/incapacity, congenital anomaly/birth defect or any other situation according to medical or scientific judgment. Number of participants with serious AEs are presented.
Number of Participants With the Presence of Anti-drug AntibodyBaseline (Day 1), Week 20 and Week 28Blood samples were analyzed for the presence of anti-mepolizumab antibodies by binding anti-drug antibody (ADA) assay. The binding ADA assay results at each visit were summarized as negative or positive. The binding ADA assay was performed in three steps; screening, confirmation and titration. The screening assay produced a result of positive or negative relative to a screening cut point. Positive samples continued with the confirmation assay, which also produced a result of positive or negative relative to a confirmation cut point. For positive confirmation samples, a titre value was obtained to quantify the degree of binding in a titration assay. Participants were considered 'Positive' if they had a positive confirmation ADA assay result.

Countries

Argentina, Belgium, Brazil, France, Germany, Italy, Mexico, Poland, Romania, Russia, Spain, United Kingdom, United States

Participant flow

Recruitment details

This was a multi-center, open-label extension study to evaluate the long-term safety profile of mepolizumab in participants with Hypereosinophilic Syndrome (HES). In this study, participants received open-label mepolizumab 300 milligram (mg) subcutaneously (SC).

Pre-assignment details

A total of 102 participants who completed the parent study (200622 \[NCT02836496\]) and met the eligibility criteria were enrolled in this open-label extension study.

Participants by arm

ArmCount
Mepolizumab 300 mg SC
Participants were administered 300 mg SC mepolizumab every 4 weeks (starting approximately 32 weeks after the first dose of study treatment in Study 200622). The final dose of mepolizumab was administered at Visit 5 (Week 16).
102
Total102

Withdrawals & dropouts

PeriodReasonFG000
Overall StudyAdverse Event1
Overall StudyLost to Follow-up1
Overall StudyWithdrawal by Subject2

Baseline characteristics

CharacteristicMepolizumab 300 mg SC
Age, Continuous46.0 Years
STANDARD_DEVIATION 15.54
Race/Ethnicity, Customized
American Indian or Alaskan Native
3 Participants
Race/Ethnicity, Customized
Asian-East Asian Heritage
1 Participants
Race/Ethnicity, Customized
Black or African American
2 Participants
Race/Ethnicity, Customized
Unknown
17 Participants
Race/Ethnicity, Customized
White-White/Caucasian/European Heritage
79 Participants
Sex: Female, Male
Female
55 Participants
Sex: Female, Male
Male
47 Participants

Adverse events

Event typeEG000
affected / at risk
deaths
Total, all-cause mortality
0 / 102
other
Total, other adverse events
34 / 102
serious
Total, serious adverse events
9 / 102

Outcome results

Primary

Number of Participants With Common (>=3%) Non-serious Adverse Events (AEs)

An AE was any untoward medical occurrence in a clinical study participant, temporally associated with the use of a study treatment, whether or not considered related to the study treatment. Serious AE was 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 persistent disability/incapacity, congenital anomaly/birth defect or any other situation according to medical or scientific judgment. Non-serious AEs from start of study treatment until 28 days after last dose (up to Week 20) are reported. Number of participants with common (\>=3% incidence) non-serious AEs are presented.

Time frame: Up to Week 20

Population: Safety Population comprised of all participants who received at least one dose of open-label mepolizumab.

ArmMeasureValue (COUNT_OF_PARTICIPANTS)
Mepolizumab 300 mg SCNumber of Participants With Common (>=3%) Non-serious Adverse Events (AEs)34 Participants
Primary

Number of Participants With Serious AEs

An AE was any untoward medical occurrence in a clinical study participant, temporally associated with the use of a study treatment, whether or not considered related to the study treatment. Serious AE was 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 persistent disability/incapacity, congenital anomaly/birth defect or any other situation according to medical or scientific judgment. Number of participants with serious AEs are presented.

Time frame: Up to Week 28

Population: Safety Population

ArmMeasureValue (COUNT_OF_PARTICIPANTS)
Mepolizumab 300 mg SCNumber of Participants With Serious AEs9 Participants
Primary

Number of Participants With the Presence of Anti-drug Antibody

Blood samples were analyzed for the presence of anti-mepolizumab antibodies by binding anti-drug antibody (ADA) assay. The binding ADA assay results at each visit were summarized as negative or positive. The binding ADA assay was performed in three steps; screening, confirmation and titration. The screening assay produced a result of positive or negative relative to a screening cut point. Positive samples continued with the confirmation assay, which also produced a result of positive or negative relative to a confirmation cut point. For positive confirmation samples, a titre value was obtained to quantify the degree of binding in a titration assay. Participants were considered 'Positive' if they had a positive confirmation ADA assay result.

Time frame: Baseline (Day 1), Week 20 and Week 28

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

ArmMeasureGroupValue (COUNT_OF_PARTICIPANTS)
Mepolizumab 300 mg SCNumber of Participants With the Presence of Anti-drug AntibodyBaseline, Negative, n=102101 Participants
Mepolizumab 300 mg SCNumber of Participants With the Presence of Anti-drug AntibodyBaseline, Positive, n=1021 Participants
Mepolizumab 300 mg SCNumber of Participants With the Presence of Anti-drug AntibodyWeek 20, Negative, n=101101 Participants
Mepolizumab 300 mg SCNumber of Participants With the Presence of Anti-drug AntibodyWeek 20, Positive, n=1010 Participants
Mepolizumab 300 mg SCNumber of Participants With the Presence of Anti-drug AntibodyWeek 28, Negative, n=1414 Participants
Mepolizumab 300 mg SCNumber of Participants With the Presence of Anti-drug AntibodyWeek 28, Positive, n=140 Participants

Source: ClinicalTrials.gov · Data processed: Feb 21, 2026