A Long-term Access Programme for Subjects With Severe Asthma

Inclusion Criteria:

- Subject participated in GSK-sponsored asthma clinical study with mepolizumab as
specified in Study 200862 and 200363

- Subject has either: completed the treatment period in the mepolizumab asthma clinical
study to which they were originally enrolled or if the subject was withdrawn from
study treatment prematurely during the mepolizumab asthma clinical study to which
they were originally enrolled but the subject has completed the study assessments at
the study visit that would have been the end of the respective treatment period.

- The treating physician requesting mepolizumab under this Long-term Access Programme
considers the benefits of treatment with mepolizumab outweigh the risks for the
individual subject.

- To be eligible for mepolizumab treatment under this Long-term Access Programme,
females of childbearing potential (FCBP) must commit to consistent and correct use of
an acceptable method of birth control, beginning with consent, for the duration of
the treatment with mepolizumab and for 4 months after the last mepolizumab
administration.

- The subject consents to receiving treatment with mepolizumab under this Long-term
Access Programme. In the case of a paediatric subject being eligible a
parent(s)/guardian will give written informed consent prior to the child's
participation in the study. If applicable, the subject must be able and willing to
give assent to take part in the study according to the local requirement.

Exclusion Criteria:

- A current malignancy or history of cancer in remission for less than 12 months
(Subjects who had localized carcinoma (i.e., basal or squamous cell) of the skin
which was resected for cure will not be excluded).

- Subject has other clinically significant medical conditions uncontrolled with
standard-of-care therapy not associated with asthma, e.g., unstable liver disease,
uncontrolled cardiovascular disease, ongoing active infectious disease requiring
systemic treatment.

- Subject is pregnant or breastfeeding. Subjects should not be considered for continued
treatment if they plan to become pregnant during the course of treatment with
mepolizumab.

- Subject has a known allergy or intolerance to a monoclonal antibody or biologic
therapy including mepolizumab.

- Subject had an adverse event (serious or non-serious) considered related to study
treatment whilst participating in a clinical study with mepolizumab which resulted in
permanent withdrawal of study treatment.

- Subject is receiving treatment with another biological therapy such as a monoclonal
antibody therapy or intravenous (IV) immunoglobulin (Ig) therapy.

- Subjects who have received treatment with an investigational drug within the past 30
days or 5 terminal phase half-lives of the drug whichever is longer, prior to
initiation of mepolizumab treatment under this Long-term Access Programme (this also
includes investigational formulations of marketed products).

- Subject is currently participating in any other interventional clinical study.