Study to Evaluate the Efficacy and Safety of MEDI9929 (AMG 157) in Adult Subjects With Inadequately Controlled, Severe Asthma

Inclusion Criteria:

- Age 18 through 75

- Body mass index (BMI) between 18-40 kg/m2 and weight greater than or equal 40 kg

- Documented physician-diagnosed asthma - Subjects must have received a
physician-prescribed asthma controller regimen with medium- or high-dose inhaled
corticosteroids (ICS) plus long acting β2 agonist (LABA) -If on asthma controller
medications in addition to ICS plus LABA, the dose of the other asthma controller
medications (leukotriene receptor inhibitors, theophylline, secondary ICS, long-acting
anti-muscarinics (LAMA), cromones, or maintenance oral prednisone or equivalent up to
a maximum of 10 mg daily or 20 mg every other day for the maintenance treatment of
asthma) must be stable. -Subjects must have a documented history of at least 2 asthma
exacerbation events OR at least 1 severe asthma exacerbation resulting in
hospitalization within the 12 months prior to first study visit.

Exclusion Criteria:

- Diagnosis of vocal cord dysfunction, reactive airways dysfunction syndrome,
hyperventilation and panic attacks, or other mimics of asthma.

- Current smokers or subjects with a smoking history of ≥ 10 pack years

- Former smokers with < 10 pack years must have stopped for at least 1 year to be
eligible.

- Any concomitant respiratory disease that in the opinion of the investigator and/or
medical monitor will interfere with the evaluation of the investigational product or
interpretation of subject safety or study results (eg, chronic obstructive pulmonary
disease, cystic fibrosis, pulmonary fibrosis, bronchiectasis, allergic
bronchopulmonary aspergillosis, Churg-Strauss syndrome).

- Evidence of active liver disease.

- History of Cancer, except for basal cell carcinoma or insitu carcinoma of the cervix
treated with apparent success with curative therapy or other malignancies are eligible
provided that curative therapy was completed -Known history of active tuberculosis
(TB)

- History of anaphylaxis to any biologic therapy

- Positive medical history for hepatitis B or C

- Subject with human immunodeficiency virus (HIV) or subject taking antiretroviral
medications, as determined by medical history and/or subject's verbal report.