A Study of the Safety and Effectiveness of Benralizumab to Treat Patients With Severe Uncontrolled Asthma.

Inclusion Criteria:

1. Female and male patients aged 18 to 75 years inclusively at the time of Visit 1 with a
history of physician-diagnosed asthma requiring treatment with medium-to-high dose
Inhaled Corticosteroids (ICS) plus asthma controller, for at least 12 months prior to
Visit 1.

2. Documented current treatment with high daily doses of ICS plus at least one other
asthma controller for at least 3 months prior to Visit 1.

3. History of at least 2 asthma exacerbations while on ICS plus another asthma controller
that required treatment with systemic corticosteroids (IM, IV, or oral) in the 12
months prior to Visit 1.

4. ACQ6 score ≥1.5 at Visit 1.

5. Screening pre-bronchodilator (pre-BD) FEV1 of <80% predicted at Visit 2.

6. Excessive variability in lung function by satisfying ≥ 1 of the following criteria:

1. Airway reversibility (FEV1 ≥12%) using a short-acting bronchodilator demonstrated
at Visit 2 or Visit 3.

2. Airway reversibility to short-acting bronchodilator (FEV1 ≥12%) documented during
the 12 months prior to enrolment Visit 1.

3. Daily diurnal peak flow variability of >10% when averaged over 7 continuous days
during the study run-in period

4. An increase in FEV1 of ≥12% and 200 mL after a therapeutic trial of systemic
corticosteroid (eg, OCS), given outside of an asthma exacerbation, documented in
the 12 months prior enrolment Visit 1.

5. Airway hyper-responsiveness (methacholine: PC20 of <8 mg/mL, histamine: PD20 of
<7.8 μmol, mannitol: decrease in FEV1 as per the labelled product instructions)
documented in the 24 months prior to randomization Visit 4.

7. Peripheral blood eosinophil count either:

- 300 cells/μL assessed by central laboratory at either Visit 1 or Visit 2

OR

≥150 to <300 cells/μL assessed by central laboratory at either Visit 1 or Visit 2, IF ≥1 of
the following 5 clinical criteria (a to e) is met:

1. Using maintenance OCS (daily or every other day OCS requirement in order to maintain
asthma control; maximum total daily dose 20 mg prednisone or equivalent) at screening

2. History of nasal polyposis

3. Age of asthma onset ≥18 years

4. Three or more documented exacerbations requiring systemic corticosteroid treatment
during the 12 months prior to screening

5. Pre-bronchodilator forced vital capacity <65% of predicted, as assessed at Visit 2
(note that screening pre-BD FEV1 Inclusion Criterion #6 must still be satisfied)

Exclusion Criteria:

1. Clinically important pulmonary disease other than asthma

2. Acute upper or lower respiratory infections within 30 days prior to the date informed
consent.

3. A helminth parasitic infection diagnosed within 24 weeks prior to the date informed
consent is obtained that has not been treated with, or has failed to respond to,
standard of care therapy.

4. History of alcohol or drug abuse within 12 months prior to the date informed consent
is obtained.

5. A history of known immunodeficiency disorder.

6. Current smokers or former smokers with a smoking history of ≥10 pack years.

7. Previously received benralizumab (MEDI-563).

8. Receipt of any investigational medication as part of a research study within
approximately 5 half-lives prior to randomization.

9. Receipt of immunoglobulin or blood products within 30 days prior to the date informed
consent is obtained.

10. Receipt of live attenuated vaccines 30 days prior to the date of randomization; other
types of vaccines are allowed.

11. Concurrent enrolment in another interventional or post-authorization safety study