Study to Evaluate the Efficacy and Safety of MEDI-563 in Adults With Uncontrolled Asthma

The primary objective of the study is to evaluate the effect of multiple-dose subcutaneous administrations of MEDI-563 on adults with uncontrolled asthma.

This is a Phase 2b, randomized, double-blind, placebo-controlled, dose-ranging study to evaluate the efficacy and safety of multiple-dose (7 doses) subcutaneous administration of benralizumab (MEDI-563) in adult subjects with uncontrolled asthma.

Eligibility Criteria:
Inclusion Criteria:

* Age 18 through 75 years at the time of screening
* Adequate contraception from screening through end of trial
* Weight of more than (\>) 45 kilogram (kg) but less than or equal to (\<=) 150 kg (\>100 pound \[lb\] but \<=330 lb)
* History of physician-diagnosed asthma for at least 12 months prior to screening
* Physician prescribed daily use of medium-dose or high-dose inhaled corticosteroid(s) (ICS) plus long-acting beta 2 agonist (LABA) for at least 12 months prior to screening
* Willingness to switch to an ICS/LABA combination product
* Dose of other asthma controller medications must be stable for at least 30 days prior to screening
* At least 2 documented asthma exacerbations in the 12 months prior to screening that required use of a systemic corticosteroid burst
* For subjects 65 years of age or older, a chest x-ray (CXR) or chest computed tomography (CT) that is normal for an asthmatic population
* Ability and willingness to complete the study to Week 66, and if needed to Week 92.

Exclusion Criteria:

* Known history of allergy or reaction to any component of the investigational product formulation
* History of anaphylaxis to any biologic therapy
* Unexplained diarrhea within 30 days prior to screening or diagnosis of helminth parasitic infestation within 6 months prior to screening
* Use of immunosuppressive medication within 3 months prior to screening. Chronic oral prednisone or equivalent up to 10 milligram (mg) daily or 20 mg every other day for asthma is allowed
* Oral corticosteroid burst or short-acting systemic corticosteroid within 30 days prior to screening or during the screening/run-in period
* Acute upper or lower respiratory infections requiring antibiotics or antiviral medications within 30 days prior to the screening or during the screening/run-in period
* Receipt of immunoglobulin or blood products within 30 days prior to screening
* Receipt of any marketed or investigational biologic within 4 months or 5 half-lives prior to screening, whichever is longer
* Receipt of any investigational nonbiologic within 30 days or 5 half-lives prior to screening, whichever is longer
* Previously received MEDI-563
* Any clinically relevant abnormal findings in physical examination
* Past history of clinically significant cardiac disease or any electrocardiogram (ECG) abnormality
* Breastfeeding or lactating women
* History of alcohol or drug abuse within 12 months prior to screening
* History of any known primary immunodeficiency disorder
* Positive medical history for hepatitis B or C. Subjects with a history of hepatitis B vaccination without history of hepatitis B are allowed to enrol
* A positive human immunodeficiency virus (HIV) test or subject taking antiretroviral medications
* History of cigarette smoking more than or equal to (\>=) 10 pack-years or smoking within 12 months prior to screening.
* Known exposure to inhaled occupational agents or fumes with an established diagnosis of occupational asthma
* History of cancer, except for basal cell carcinoma or in situ carcinoma of the cervix treated with apparent success with curative therapy \>=12 months prior to screening or other malignancies treated with apparent success with curative therapy \>=5 years prior to screening
* Stable dose of allergy vaccination regimen for less than 30 days prior to screening
* Subjects unable to demonstrate acceptable inhaler and peak flow meter techniques.